First of all, welcome to Aximsite!
Unless you just really need/want the upgrades, I'd stay where you are at. I have an X50v. I tried upgrading it to WM5 once. I was not happy with the results and so I've been back with 2003 ever since. I'm perfectly happy staying put until a fix comes out. If it ever does come out that is... Anyway, the choice is yours and yours alone. I personally would leave well enough alone.