Does anyone know what the highest rank is you can work towards in the Demo?

Not sure, but it resets me any time I exit out.

The highest I've actually seen was Cpl.

SFG

SFG???

Do you mean SFC - Sergeant First Class?

Does the DEMO stop at the top of the Enlisted ranks: PV2, PFC, SPC, SGT, SSG, SFC, MSG, 1SG, SGM, CSM, SMA? Or does it proceed through Warrant Officer: W01, CW2, CW3, CW4, CW5 then Officer: 2LT, 1LT, CPT, MAJ, LTC, COL, BG, MG, LTG, GEN, GA?

I am currently at MSG, guess I just need to keep playing and see for myself.

The first night the demo came out, I played it late, or earlier in the morning more like, a couple guys had been playing it constantly and were ranked up. I don't think my eyes or Xbox can take that kind of abuse. I'll wait until I can save my status.