I have both the Bloog MF shorty and the V4L Diamond Series regular. The draw is very similar in both and you don't need a primer puff in either. The cutoffs haven't affected me in either one.
The major difference to me is the cartos. The BMF cartos have some issues that are being highly discussed on the Bloog forum and hopefully will be corrected soon, but when the BMF cartos work, they ROCK!
BMF cartos don't work well for me on the Diamond Series batts, and the V4L cartos don't work well on the Bloog MF batts to me - every now and then I get lucky and can mix the two, but rarely!
The BMF cartos give out much more vapor to me and I like them better, however I will continue to use the Diamonds with the Cool carts as well.
Both of these batts have a new technology that resembles actual smoking to me more than anything else I have tried. I do like the rubber finish on the Bloogs better than the shiny finish on the Diamonds, but that's just me.
If you want the closest thing to actual smoking I would say you can't go wrong with either one.