I can relate some other things that I have noticed, owning both boats. The D drive (I'm referring to the open bow D drives in this post) is great, I'm taking it out tomorrow for probably the last time.

I love this boat. The wake is better than the SX right now, mainly because it's dialed and the SX needs to be trimmed out a bit. The D drive does have a nice pocket about 70-75 ft off. The V drive is not as peaky but I need to try it with equal bow weight to give it a fair evaluation. 750 in the walkway.
There is a ton of useable storage in the D drive. The side pockets with netting are so handy for flip flops and stuff. Making people get up off cushions to access storage really sucks. I did use a walmart bag under a rear seat cushion as a trashbag, it works pretty well. I don't have the V drive storage/useage figured out yet. Having to open the hatch every time is a pain, esp. since I fixed the latch, which has an inconvenient handle. The space is there, but I might just put a sack in the trunk and put some stereo stuff in the V drive space. 8 x 12's or something.
The trunk on both boats is awesome, my SX trunk opens straight up for better access. My Epic 22 trunk lid doesn't stay open, and it opens to about 70 deg. This was fixed on later Epic D drives, Cal's boat has the improved gas cylinder, it has one center cylinder and opens to 90 deg and stays open! That is something worth posting a pic of Cal, it would be a cheap, useful mod for older boats.
There is less room under the seats in the V drive, which suprised me. I thought I would be able to put a bow sack up under there, but I don't think so. I don' wanna crack fiberglass.
The side storage is almost the same on both boats, but it is bigger on the D drive. The V drive has a nice wall for amp mounting in there. It is a beoch to install and work on equipment in this space, both boats.
The cooler on the V drive is not as nice. It is not a hinged cushion, so you have to pull it off, kind of tight if the jump seat is installed. It is also about 1/3 smaller than the D drive cooler.
Both boats drive very well empty, the V drive is snappier than I expected. The SX has a different transmission, 1.43 or something vs 1.23 on the direct drives. I get 6109 rpm at about 36 mph on PP, which I have NOT calibrated yet with a gps. This is with PP installed, and a 4 blade OJ nibral prop.
The D drive gets 5800 rpm at 37 mph, on a PP that is uncalibrated as well. 4 blade OJ nib with .080 cup.
The tramp top will be cooler on the V drive, because the back seat is further forward and will shade more people back there. Too bad you can't get those anymore, it would be worth getting one made.