Ok, after much tweaking I've finally gotten my FPS to a respectable level and the game is now playable AND beautiful.

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System:
AMD Barton 2500+ OC'd to 2.3Ghz
1gb PC2700 333Mhz ram
GeForce 5700 Ultra 128mb w/ 56.64 drivers
SoundBlaster Audigy Platinum 5.1
480w PS
(various other pieces of hardware)


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In Game:
Sound: all on full
Graphics: all on high, lightmaps on - 800x600x75



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BFV .con file edits: (these lines were either added or modified)

VideoDefault.con:
renderer.allowAllRefreshRates 1

Default.con:
Game.GameLevelPath BFVietnam/Levels/Ho_Chi_Minh_Trail_alt/
game.soundbuffersize 1000

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Card/AGP Tweaks:

Coolbits Registry Hack
AAS (AGP Aperture Size) 256mb - you have to change your BIOS settings for this one


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Results:

The results below are in the following format: AAS/GPU speed/Memory speed/ 3DMark 2003 score

8/300/906/2900 (this appears to be the default GPU/MEM setting for the card - 2D Performance option in the "Clock Speeds" section of your NVidia control panel)
256/475/906/3223 (this is the GPU/MEM setting for the 3D Performance option in the "Clock Speeds" section of your NVidia control panel)
* 256/553/950/3442
256/553/1.06Ghz/Unstable

My final FPS in BFV using the indicated settings were:

Outdoors: 85-150 (avg around 90)
Indoors: 42 - 120 (avg 47 inside the largest/most complex building)


I'll be testing these settings some more, but right now the card is very stable and running at a normal temp. when under load. The 3DMark 2003 score was MUCH higher than I was initially expecting. I can run my resolution at 1024x768 and if I turn lightmaps off I can keep my FPS very close to the 800x600 settings.

The reason I kicked my AAS number up was that, after much research, I determined for my system that was the most beneficial setting. The amount of RAM reserved is negligible considering I have 1gig and it does appear to make a minor difference in FPS. I had read on another board that setting the AAS to 8mb would help, but as the stats show it really didn't.

Hopefully this information will help someone.