I hit 5 psi by 2,600 - 2,700 rpm, and 10 psi by 3,000rpm
I am using stock heads and valvetrain, with no float, and I understand lot's of TECII guys are running 10psi to 6,800rpm without float. I have been to 14-15 psi on a 40 degree day with no float (also we are at 6,000 feet above sea-level).
I did get a ride today (at a local meet with 30 cars there) in a 26psi 98RS with 2.2T shortblock and lots of valve float above 5,000rpm, and even at 21psi he still had the same problem. His car didn't feel as fast as mine, but we raced his 8:1 CR 2.2T at 21 psi against my 10-12 psi 9.4:1 CR 2.5L and were dead even through the 1st 3 gears, that's how much power he lost to valve float.
His 2.5L built motor goes in next week, with new valve springs and 8.5:1 forged pistons. So he'll beat me by then...