The innovations of LR LR 4 to 5 mainly stand out the improved range correction and the radial filter. Possibly even the perspective corrections. The rest is not really the bringer.
But then more than 70 EUR are quite steep for update's.
Absolutely annoying is that the new version is not yet stable. Had already some crashes in the development module. With the beta version that was not the case. As bugs are probably still built for Final ... :-(
Therefore, only two stars. If it hopefully is a bug fix, I draw out one or two asterisks.