I like how quick they were to reply when we had questions, even though it was at 11pm in their time zone! They are very responsive so far - great communication between us as well with our designer who is helping build out an app from scratch that will look amazing once finished (and hopefully launch!).
The price seemed high but since then have received more quotes which seem fairly similar; however there's no way of knowing until after contract negotiations if you're getting good value or not unless prices go down further than expected (which could happen). We used them because they offer free trial periods before any contracts get signed etc., plus all work gets done remotely by developers around Australia/New Zealand (so less chance of delays due to distance issues).