Powercal?... no I don't have one. I have a mobile in my pocket .
I am comparing my power numbers and times on certain climbs I have done many times with power meters and without. I know my best off 5 minute wattage is 470w... Strava gives me a comparable reading on the climb. I find the steady climbs are best like this one http://app.strava.com/segments/708976 or this http://app.strava.com/segments/709036 ( no way ever I will match the guys up front though...ever!!!... but the top guys are Div Nat 1 / 2 riders ... they race with pros, I dont ) . If you have your weight dressed and ready to ride and your bike weighed with half a bidon then it is pretty close... ok not perfect but good enough for me.
I have 4 climbs that I will test on this year... a 1 min, 5 min, 7 min and 30 min. They will tell me if my training is going to plan.