Depends alot on the years of both cars. Newer 911's, depending on model would be a good run for a stage 2 STi from a roll. The Newer NA 911 (96 - 04) models will run high 12's to low 13's and trap 105-110 depending on trim level. The Brand new 997 model (the 05 911) is a little bit faster but not a whole lot, they'll pull pretty consistent 12's and trap over 110 stock. I'd guess the 911 was probably stock, modded he would have likely shown you the taillights, especially at higher speeds.
As far as the Boxter goes, if it was an S model (which it probably was if it kept up with you at all, the non S model is pretty slow and would get smoked bad by a sock STi) it may have been lightly modded. The older model Boxter-S's run in the mid 13 and trap a little over 100 stock, but the newest model that just came out for 05 is a bit faster, and might give you a decent run from a roll stock.
Either way, nice runs, its always fun to get cars like that to mess around.