Yeah I think 8m30s BTG is achievable on a clear run.
At 2m45s I was going at some serious speed through fox hole and as I usually take the line to cut the kerb over on the left at the top I didn't expect the Lotus to slow down so much! When you take that line (especially over that kerb at speed) you do get pushed over to the right. I also had that white Porsche wanting to overtake me too. The PBMW BBK definitely saved me, there is no way the standard brakes would have stopped me in time.
I've not driven a 335 for a long time so can't really comment on how their brakes compare to the PBMW ones.
Bilsteins are very good indeed but my car still feels too soft - I think M3 bushes and stiffer anti roll bars will fix that.