You could spend all day replying to your question, but no one would really reply here as most are nevo users not RTI, however i can state that programming q50 and s70 is very simple, i know of two installers who used URC MX-3000 and RTI U2 remotes and won't go back to either brand. Too much to go through in programming not straight forward enough. Why don't you check around for your local distributor and ask for a trial to compare.
You can customise the nevo as much as you like, 2 way rs232 is only coming on board but Nevo has only been around for about 5 or 6 years so it's done a good bit in that time. RTI and URC have been around since the early 90's.
As far as reliablily goes no body can ever say you won't have problems or issues when it comes to installing remotes be-it any make or model!!! But i haven't had any major breakdowns on the remotes. Main issues are down to people not understanding z-wave technology but if its line of sight control then stick to IR. The new generation of remotes are much better than the previous model.
99% of all IR codes are in the Nevo Database, if it isn;t you can convert from other remote manufacturers or enter a hex code or if you have the original remote just point it at it.
