Madfloyd, I've complained about a similar problem on these forums as well. Specifically, a relatively lightweight tonal balance, the bass doesn't have enough impact or fullness for me.
I'm not ready to give up on my Scoutmaster with 10.5i arm at this point, however. Many on this forum feel VPI's sound fine, so I'm willing to do further work on my setup.
As for the problem, I suspect the relatively low mass of the VPI arms could be part of the problem, you do have to use a fairly high compliance cartridge with these arms, particularly the 9" arms. Changing my 9 arm to the 10.5 arm helped out the bass to some extent, the higher mass of this arm is likely helping here. I also recently added about 40 lbs of lead weight to the Bright Star Big Rock under my tt, this further helped out the bass.
Beyond this, who knows where the problem lies. It could be cartridge alignment, the platter, rubber belt (I changed to thread drive), acrylic platter, tt isolation, cartridge, my phono stage. Every one of these things has been mentioned as possible culprits by audiogon members answering my posts. There are so many variables in tt setups, its difficult to pin it down to any one thing.
I've also heard from some who don't care for the VPI sound, it seems they think the VPI lacks musicality. I wonder if this is a lack of satisfying warmth in the lower frequencies.
I next move will be replacing the Sovtech 12ax7s in my phono stage with Mullards, then a different cartridge alignment with the Mint Lp. If I'm still not there, I will be changing out the capacitors in my phono stage to Mundorf Silver/Golds or VH Audio TFTFs. If the bass is still lightweight after these mods I will be much further inclined to blame the VPI. Still, a better cartridge and the super platter may be needed to complete the setup.
Based on my experience with my VPI to this point, I would have to say the VPI Scoutmaster is not a plug and play unit, its simply not a finished product without all the upgrades. The upgrade path VPI offers makes it easier to get started, but it sure sucks to think you aren't getting all the turntable has to offer without those upgrades. I have a feeling the Scoutmaster is going to end up being at least a 6.5k investment rather than the 2.5k investment I initially thought it would be.