The monopod alone makes for a very compelling feature - I have been trying the Whiskey 3, AX AICS, Drake's MSR Gen 2, McRee, XLR - Ergonomics are great on all, most comfortable is AX and Whiskey 3.
Important features are:
1. An oversized trigger box - make sure X-mark pro, Jewel, and Huber fit w/out contacting the chassis - they are quite big
2. Folder
3. LOP and Height-adjustable buttpad
4. Flush cups
5. Monopod
6. Larger cutout for aftermarket recoil lugs.
7. Top rail is good, but optional. Bottom rail is great for bipods such as Atlas or LRAccuracy. Side rails - maybe make them removable, i.e., the A1 forearm is basically perfect.
8. Movable or different-sized grip - as aftermakret triggers vary in their trigger shoe position, you want either a movable grip, or different-sized versions of it - basically, the MSR Gen 2 has too long a distance between the back of the grip and a X-makr Pro (CG22) trigger to use it comfortably. AX is a bit long, as well.
9. Thumbshelf for shooting non-pistolgrip style - Either like the shelf on the Whiskey 3, or something like
http://accurateshooter.net/GOTW/eliseor5topx640.jpg - The thing sticking out above his trigger finger. Maybe just a threaded hole there with a removable blocker would do it.
10. Please make the magwell big enough to take AW (not just AICS) mags - some of my rem's feedramps are cut for that.
I understand that 8 and 9 would drive up the price - 8 more than 9, I think...
Honestly, if you had features 1-5, and the grip was similar to the DTA grip, I would immediately get 1, and if it worked, I'd get 2 more for the other Rem 700's in the stable, and switch my pending build to it from the Whiskey 3. I would also try to retrofit it to the Gen I M2008 that I have, if I could - but that is optional.