The customer service was excellent - they were very responsive when we had questions or needed help with our implementation process! They are also willing partners in helping us understand how their product works so that it can be integrated into ours without too much difficulty (we're using them as an API provider). We have not found any specific issues yet but I'm sure there's something out here somewhere :) Their documentation could use some work; however this may just reflect my own lack thereof rather than theirs :P But overall great experience working through all aspects from pre sales engagement right up until post go live support for integration purposes etc..