I haven't been able to play recently as my video card appears to have blown up but the honest truth is that the version I played was not as good as SH3. It may be a little prettier and have some neat functionality (which quickly becomes tiresome...like walking around the inside of the sub), the fact that you must be connected to the net and the weird bugs it seems to have make SH3 a better buy right now, if you like the Atlantic Theater [SH4 if you prefer the Pacific].
Mods will eventually make SH5 better given the great graphics...but they are tricky to get installed for some reason for me. Neer managed to get it right before the vid card in that machine gave out.