OP-1 : There's nothing like it.

I've had it for a while, but like me and almost everybody who buys one, you will probably sell it after a while. If you keep it, it's because you're never short on money for gear and you don't expect it to sound amazing. I regret selling it every time I travel, because in those cases it's a producers/songwriters coolest friend (laptop would still be better, but not as fun) The main problem is that it just doesn't sound good. It's usable, but even the most basic synths for 200 euros probably sound way better. It's a really inspiring tool, it's great fun while traveling, you'll probably write many songs on it, and then sell it, because you're not gonna use it on many recordings (no that artist you're thinking of that uses it on that one album you like does not use it all that much either). Having said that, if you always wanted one, buy it! Because after having it a while it'll lose it's appeal and than you can finally move on to spending your money wisely, like buying that VST you need, or an amazing sounding soft synth.