Although it would be easy for me to say XenForo is the answer to all of your problems, it would also be fair to say that obviously IPB ultimately should work flawlessly without these database errors. It may be that you have a server or hosting issue. In which case, I wouldn't want to give you the expectation that XenForo would fix that problem and you then find you've got the same problems.
So, I think it would be wise to get to the root cause of the problem before making a switch that may ultimately have the same issues.
However, if we forget about all that for a second, we are all obviously going to say that we think XenForo is better. I suspect if you asked the same question at their forums they would say IPB is better
But yes, XenForo is better
We find it is incredibly friendly to use from an Admin and User point of view, the support here is absolutely fantastic, and customising it is probably one of the easiest forum systems to customise.
As for the transfer and permissions, there's lots of people here who can help you with that. I personally have experience with migrating from vBulletin to XenForo. Would be happy to help if you need any advice.