i was upgraded from cat 4 to cat 3 last year on points i won, for me the area where i seen the most improvment on my power numbers over the season was 5min power, good 5 min power will have there of there abouts coming up the finish.
Raced 3 times as a cat 3 this year so far placed in my 2nd race, power numbers are all up about 10% across the board, races dont seem any harder just bigger bunches and postioning is more important, as a strong cat4 last year i could ride at the front of the bunch the whole race, dont think i have the numbers to do that in cat 3 with all the attacks
went from about 3.8 watts/kg to 4.2 watts/kg ftp cat 4 to cat 3
I'm Cat 4 and last summer my peak hit 4.2 w/kg. My "A" race saw me get 4th in TT about 13 sec away from 2nd place and 45 sec away from 1st. On the circuit race I got dropped (barely, but its all the same right) on the last hill by a lead group of 15 guys. Tried to bridge back but strong wind, gap got bigger and finished 2 minutes down. Next day 80 mile mountain stage was killing it, then on some big rollers halfway through, at 8000 ft elevation I was behind a guy who got gapped and as soon as I tried to go around, the first 8 guys saw I was gapped and put the hammer down and dropped me hard. I never caught back on. Bike racing is so incredibly humbling. It is such a tough sport.
So, 4.2 w/k was NOT good enough to win that Cat 4 stage race. Although both times I got dropped were mainly positioning errors on my part (not being in the first 5 guys when I needed to be). I didn't have the strength to make up for my lack of tactical savy. That has changed:) I will say the top 5 guys were pretty dang fast. Especially going uphill. They all were about 1/2 my age too. Lol.