Hum, let me see.
Started the campaign just before 3E came out, the characters had gotten to around 4th level average by the time we switched. Been playing ever since. What is that now...3 1/2 years real time. Started with 8 players, down to 4 now due to removing one player due to bad attitude, 2 moved and 1 is not 100% committed at this time.
In that time they have gone from 1st to around 34th average some lower by a few levels, one higher by few levels. (death sets back all that approach). Only about a year of campaign time has passed.
We play 1-2 times per week, 4-6 hours per game day. Been that way for while. Never really had a campaign progress like this one in all my years of DMing. Next time around I'll know how to run things a little better and different probably do a variant rule about training time to slow it down.
They have taken very little downtime, and taken on challenges much greater at times than they should have and survivied due to luck and some times tactics. Only one player (the highest and one never to have died) runs from things if judged too hard or dangerous, the others fight to the death even if pressed. Many of them now are taking downtime or handling character related story-lines, quests etc, the group basically split up for the winter, and made the DM's life hell for a change.
RD