Anyone train with a powermeter on the bike? Is it worth it?

No, I don’t have one.

Yes, it is undoubtedly worth it according to all the road cyclists I know.

Are you biking outdoors? As a cross training method (coming back from injury), I’ve found I can enjoy cycling indoors on a turbo trainer which adjusts the watts automatically. I bought an entry level model and find it more than sufficient. But all the “real” cyclists friends I follow use a power meter. Then you can design works of x min at y watts etc.

I’ll also add a cadence monitor (eg from Garmin). I usually keep the cadence relatively high, 90-100rpm on the efforts. With a smart trainer/turbo trainer I use MyWhoosh which is a free alternative to things like Zwift.

If you’re serious about cycling then yes. If it’s just for cross training don’t stress it.

Powermeters are great. They're usually pretty accurate but not always to a T. The reality is that you still have to be dialed into effort &, if your goal is to get better on the bike, you just need to keep working it. It'll help you dial into the right effort but it's like a running watch -- you could be holding yourself back or pushing too hard just to hit the "right" number.

Yes it's a must-have, if you want to train seriously. You can get a single sided one for $250. But I agree with the comments that indoor training is more time-effective and in some ways more fun.

Or try the ultimate test, time yourself on a hill climb. Because, unlike the questionable calibration of other devices, the stopwatch doesn't lie.