I just love it.
I use it at least half the time I plugin.
Are you skilled with synths? There are lots of commonalities between synthesizers that can be learned and travel with you from one to the other. I enjoyed rapture before going through Syntorial, but after Syntorial I have a much better chance of going for something and getting it.
I do use rapture pro with a touch screen, which adds specialness.
People are right that there are some issues, but I'm able to have tons of fun with it. I always record audio with the midi and so have to turn up my sample buffers so my computer can keep up when the song gets rolling. Using my Roland gr20, lots of data gets sent and it can cause dropouts of I let it get too hot. I will back off my guitar if the processor climbs too high.
I wouldn't let rapture go. The soundscapes it produces are chilling.
If I could improve it, I'd make it so I did not have to fear processor overload while using it.