My 4x12 (Marshall MF with V30s) is making a farting sound seeing as they are now fairly old and I don't like my 2x12 (Marshall 1936) due to the G12T75. I find them too fizzy. So, I going to fix my 4x12 with some new speakers at a later date but, first I want to improve my 2x12 seeing as I use it at home and at gigs so it has to improve. Then I can decide what I wan to to do with my 4x12.
In the grand plan I'm going to change the speaker in my 2x12 but, if speakers don't fix it I will grab a Zilla cab. So I need to get some new speakers.
About 99% of the time I am playing a 8 string, so I require something which can really hold the low end nice and tight with both my heads, ENGL savage and Laney Ironheart.
Since you like the V30s, I'd stick with them. If not, try some eminence speakers, like the Man O War or the Blackpowders.