This year I've raced P123s with a few good 1s in there; Cat 3s (2 "real" races, Ninigret and Somerville; Cat 3-4s; Cat 4-5 training race.

4-5s - moderate pace under pressure (25-28 mph), relatively high amounts of "off" time. I haven't looked at the data too closely but to give an indiciation: avg HR 145, avg power 154 (np 235); avg speed 24.2 mph. This was last Wed night at Bethel. Some riders thought it was a "hard race". I did this race because I'd just ridden 70 miles, was suffering from heat exhaustion, sun poisoning, and cramps, and I didn't think I could finish the race. I could climb at race pace with my legs twinging (they were threatening to cramp from lap 2 on), held on for 5 points sprints, and led out the final sprint.

3-4s - moderately high pace under pressure (28-30-ish), less "off" time (few laps out of 30). Avg HR 154, ap 179 (np 267); avg speed 26.1. This at the same course as the 4-5s. I placed 2nd in this 3-4 race, and it was the highest pressure race (my own goals) I did this year.

3s - moderately high pace under pressure (30-ish), less off time (0.5 laps of 15). Avg HR 169, ap 201 (np 235), avg speed 27.0. This at Somerville, should be the hardest or second hardest race I'll do (Harlem Crit is the other one). I was totally done at 400m to go and didn't sprint.

P123s - training races only so far, at least that I've completed. Very high pace under pressure (32-35+ mph, 38-40 in cross-tailwind conditions), almost no off time (less than 1 lap in 33). Avg HR 164, ap 234 (np 280), avg speed 25.6. I was active in that race so not just sitting in. Led out sprint, never sprinted. No breaks succeeded. This from a few Tuesdays ago.

The good Cat 3s, like the ones that used to be 1s or 2s (former winners of Cat 1-2 Killington, Fitchburg, big big big races), they sit in for a while, doing absolutely nothing. But when they go, they go really, really hard. If they get away, fine. If they don't they'll sit in until the last few laps. They can usually place in 123 races.