hello amit,
the 7206 is has reached its end of sale, and might not get support in future.. The VXR has a faster bus and will take faster processors - with a non-VXR you are extremely limited as you will struggle increasingly to get bugfixed software as the chassis is no longer officially supported. You're also limited to processing engines that won't take enough RAM for a full internet routing table for much longer.
since it is going to be only for the lab, you can opt for either of these, but if they are of the same price, i would definitely go for a vxr model !!!!
hope this helps.. all the best.. rate replies if found useful..
Raj
