the v5 is not adjustable unless you mod it. after it dies, which takes a really long time, the mmap adjustable vcube 5 core mod is really good. who wants to break in a new v5 when all you have to do is cut the sucker up and replace the core? or, if you want to spend like 75 bux, you can buy one from smaz cube store.
to get a piece out, spread the outer layer as much as you can until you can get your thumb in between the UF center and UF right edge. push the UF right edge toward the corner really hard and then the piece will pull outward. rur'u' works too. if you force the corner to cut, it gets all locked up crazy and the UB right edge pops out easy
the corner mod is definately worth it. i sanded down the bumps first, noticed a big change, but heard of sanding the corner stalk. imho, corner stalk is pointless. getting the lube out that comes with it (the crap that gets gummy almost immediately and gets all over the outside) and relubing with d39, if you havent cleaned it out already.
CRC is fine too. i only lubed my vcube with crc so far, even with all the other lube available, only because the propellant has a marginal effect on the imperfections of the molding process. seems to work good for me. just be careful not to brick of course, just go slow and get it everywhere as evenly as possible. do all the sides. much like the xcube, it takes about 100+ solves for it to start feeling amazing. after like 500+ it starts becoming looser. once its loose, you can rock it!