We used to use an old version called v2 but now we are using V3 in production which has been very good so far! It's not perfect by any means as it will need some customisation if you want certain things changed (like adding your own fields) however this isn't too hard or time consuming once done. If I had one thing that would be improved then its how long does each indexing process take? Also maybe make sure they have people available during these times rather than just having them online when you ask about support like myself. They do offer after hours calls sometimes though which can still help with getting answers needed - also there is usually someone around who knows what they're doing which helps immensely at least from my side.