waaaay better than the GT-10 - no 'cocked wah' sound!
I have been using amp modeling gear for years, from the lowly Behringer V-Amp 2 to the Line 6 POD X3(I took a pass on the HD series - Line 6 rushed it out there door with HUGE issues, both hardware and software, plus they threw us metal guitarists under the bus to feature lots of 'boo-teek' amps that only rich lawyer/'wannabe bluesmen' even care about) to the Digitech GSP1101 rack unit, plus all the computer-based systems like POD Farm, Amplitube, Guitar Rig, etc. I have also used several amp modeling amplifiers over the years. And, yes, I have owned good old-fashioned tube amps as well... The KEY to amp modeling is KNOWING WHAT YOU ARE DOING. I know that's a blow to alot of guitarist's egos(what? musician's have egos?! LOL), but despite all the media hoopla, for a SERIOUS pro-quality tone, amp modeling gear - no matter from what manufacturer - is NOT 'plug-n-play'. You DO have to learn it's nuances and spend some time with it... and frankly, in this day and age of 'I want it all and I want it now', people won't spend the time and make snap judgments that amp modeling 'sucks' or that it's too complicated, saying 'I don't like to fight for my tone'. Well Gomer, the world needs ditch diggers too, so... ;0)
The build quality is there, of course - hey it's a BOSS! I think the phrase 'built like a tank' was invented to describe BOSS gear... there's a reason you find BOSS gear on LOTS of touring pro guitarists rigs, much more so than trendy 'boo-teek' gear - they always WORK and you can buy em anywhere should something need to be replaced(which is rare indeed). It can sound like a million bucks, but if it breaks down every third gig, then it just doesn't matter. You can RELY on BOSS gear.
The first thing one will notice different about the GT-100 from the GT-10 is the dual LCD screens. The brown/orange display is easily readable and can be adjusted to taste regarding brightness and contrast. It also doesn't temporarily blind your eyes like the overly-bright blue GT-10 screen often did when looking into it on a dark stage... The reason for the dual screens is that you can pull up your entire signal chain on the left side, then see the specific parameters of whatever is highlighted there, on the right side. It might not seem that helpful when just reading a description of it, but when you see and use it in real life, you'll instantly appreciate it's usefulness. If there are more parameters available than can fit on one screen, you'll notice the familiar folder tabs, just like on the GT-10, so you can just hit the 'page' button to scroll over.
The effects are top-notch - again, it's a BOSS. If it's not there, you probably don't need it... and YES, it has 'spillover' on time-based effects like delays and reverbs, so if you're switching quickly from one patch to another mid-song, your repeats aren't going to cut off unnaturally. I like the feedbacker effect, enabling me to play with feedback as if I'm live next to a huge wall of amps, even though I'm recording silently in my home studio(I've recorded a handful of original music CDs using modeling gear since 2006). The bullet-proof pedal is there for volume control, wah effects, or any other effect as well, as EVERYTHING is tweakable and assignable. You can assign anything to anything, so if you wanna have your delay repeats ramp up, boost your overdrive, add some chorus or flanger by hitting a single button, you can! The ACCEL button is something I usually assign to something else... at times, BOSS seems to be stuck in 80s shred territory for some reason(I'm guessing that's still 'big in Japan', no pun intended), so by default ACCEL has these weird laser-beam effects in it that quite frankly, I'd NEVER use - so I don't. I usually program the ACCEL button to a feedbacker. It's your choice - which is what modeling gear is about - CHOICES. YES, there is the ubiquitous looper on there as well - isn't there a looper on EVERYTHING nowadays?! I only use it to record a guitar riff, then I can tweak the tones at will while IT plays the riff over and over... but that's just me.
The amp modeling itself is top notch - although for me personally, I only tend to use about a half dozen or so, so there are ALOT more that I just don't need... but maybe YOU do, so they're there. BOSS doesn't use the actual names of the amps being modeled, but if you've been around at all, you know a Marshall or a Fender or a Mesa Boogie when you hear it. hehehe ;0) The dreaded 'cocked wah syndrome' that plagued the GT-10 is GONE! YAAAAY!! I know a BUNCH of guitarists that shied away from the GT-10 because of it, but now there's no reason to NOT give the GT-100 a try. There are quite a few 'advanced' amp models as well... why they' are 'advanced', i have no idea, but there are many, many choices as far as preamps go. There are also many, many choices as far as speaker cabinets to use, different microphones, all completely positionable, just like in 'real life'. There are also 'custom' settings, so you can design your own preamp or speaker cabinet tones - it's ALL up to you. Or, you can just leave it at the default configuration and just twist the bass-middle-treble-presence-gain-volume knobs, just like on a 'real' amp.
And now for the BAD: yes, there is ONE thing where BOSS completely DROPPED THE BALL. I am about TRUTH, and as they say, the truth shall set you free... THERE IS NO NATIVE GT-100 SOFTWARE FOR DESIGNING TONES ON THE COMPUTER. WTF?! This is 2013, BOSS/Roland! There IS an independently developed GT-100 editor software made by a guy with the screen name of 'gumtown' that can be downloaded for FREE to work with your GT-100 on the computer(just google 'BOSS GT Central forums' and you'll find him). I have it and it works great - but come on, this is just freakin' RIDICULOUS! Line 6 has a thriving online community based around the POD line of modeling gear... why BOSS has completely missed the boat on this is beyond me. I literally scratch my head in wonderment at how they could NOT wanna capitalize on *cue dramatic music* THE INTERNET. Okay, I'll step down off my soapbox now... but COME ON BOSS, GET WITH THE PROGRAM!!!!
I know this has been a long review, and quite frankly, I'm just scratching the surface on what this amazing piece of kit is capable of doing. There is NOTHING you cannot do with the BOSS GT-100. You can record your next hit single while the baby sleeps in the next room, play live worship at your church on Sunday, or tear down the club on Thursday Thrash Night. You can plug it directly into your computer's USB port, run it direct into the house PA system, or run it into that iconic Marshall stack via the 4-cable method and mic the cabinet, 'old school' style. Simple or complex, again, it's ALL UP TO YOU.