Not the best, but not the worst
I just got my SynthStation 49 last night, and I haven't had time to really dive into it deeply yet, but here's a quick rundown of some apps I've tried and my experiences thus far -
Akai Synthstation App - This is a REALLY bad app, the sounds are horrible, functionality and intuitiveness of the app is very poor. I suppose every Synthstation owner will buy it, but really, it sucks.
GarageBand - This worked pretty well, but I wish the record and stop buttons would trigger those functions in the program rather than you having to tap on the ipad itself. Drum pads don't seem to be assignable, but other than that, it seems to work.
AniMoog - This was really the app that I wanted the Synthstation for, the Moog folks have made a great tool, and it works very well with the synth station. Again, a little more hardware integration in terms of the physical buttons and pads would be nice, but overall, I'm happy with how this works thus far.
Magellan - This app also worked very well with the synthstation, and it's got great sounds. It's well worth the price of the app.
Sunrizer - This app works very well, has great synths, tones, and functionality. Definitely buy this one.
Korg iMS-20 - A fantastic app, the sounds are awesome, and the features are truly like that of the old MS-20. Again, it's a shame that you can't assign the pads and other hardware buttons to other functions within the app itself.
Korg iPolySix - - I haven't tried this yet, I'm hoping to get to it this weekend.
Novation Launchkey - I haven't tried this yet, I'm hoping to get to it this weekend.
Pianist Pro - I haven't tried this yet, I'm hoping to get to it this weekend.
Overall so far, the SynthStation is a decent buy if you already have an iPad, and you're used to playing on a smaller USB keyboard, it's worth picking up. My main complaints are the completely awful Synthstation App, and the lack of being able to assign functionality or use dedicated hardware buttons and pads to perform the functions that they could with other apps. If you primarily plan to use this as your main keyboard, you'd probably be better with the Akai MPK61, especially if you're going to be running it into your laptop rather than your iPad. However, if you're looking to tinker around with a bunch of iPad apps, and want something that will power the iPad and give it a dedicated dock, the SynthStation is not a horrible solution for a set of keys to drag to practice or a friends house to have fun with. I even think that after getting the hang of all the issues with it, you *could* even be daring enough to play a few shows with it as well.