LW 5 is still developing. LW 5.0 was released start of year with very basic functions/tools. LW 5.1 added a few more. LW 5.2 finally added some old & new tools including an improved junk file recognition. However, I think it would still be best waiting until LW 5 develops a little more before updating / upgrading.

The Pro/Basic argument is not an easy one. At least for now I'd suggest LW 4 Pro would be a better option for an 'experienced' user. (Many more tools.)

Personally I'm a person who uses most of LW 4's tools. LW 5's less tools is not inviting to me to use LW 5 on a full-time basis.