I think a win over Florida nets LSU a national seed. They would likely be Top 8 in RPI ... have the #2 conference record in the SEC ... won 2/3 from Ole Miss (one of the competitors for a national seed) ... and would only be the second national seed from the #1 RPI Conference.
Yes, LSU has some warts on their resume. Particularly NC RPI and NC SOS, as well as record vs. RPI Top 25 (would be 6-9 w/ win over Florida) ... (LSU's record vs. RPI Top 50 would be 14-11). But so do the other contenders. For example, Rice is 3-6 vs. RPI Top 25 and 9-11 vs. RPI Top 50.
Brian