Because im still very new to DIY, i find myself searching for alot of flavor profiles especially X flavor X brand V1 vs V2. alot of the time i find that its the Diketone free or Butric acid version, but a lot of times they taste alot different. However some of them could be subbed for the other without much change, so ive found. i vote to start a mega thread comparing V1's to V2's. anyone down?
I think the important thing to consider with v2's is the butyric acid addition, and how that can be limiting to how high you can push that flavor up before it gets a little nasty. If you are trying to get a v1 profile with a v2, add a little cream (vienna/fresh cream usually) in combination with the v2 to soften it up a bit.
The only pair of matching v1 & v2 flavors I've tried is Capella's Vanilla Custard. I have a 4oz bottle of both, and very much prefer the v1. I got the v2 first and I loved it, right up until I tried the v1 for the first time. I wish I knew some local DIY-ers I could trade with to offload some of this v2, as it's going to be years until I get around to using it again.