I'm looking for some people's personal experience with power meters as the Internet seems full of bias views. I'm only interested in duel system and my budget is around £800 and I have a garmin 820 edge my bike is a 2017 trek emonda carbon, I like idea of the vector peddles but mixed reviews.
I have an Infocrank for sale in the classifieds today - way under your budget...
Vectors would suit, they've fixed the breaking pods in the newer version. they aren't really movable between bikes. You will always hear disproportionately more negatives. It's a mature product with common cleats.
I also like the Powertap P1s, but the cleats are not fully Look KEO compatible.
I've broken two first generation Stages.
I personally like my Powerpods.
There's quite a thread going already, that you may like to read 😉
http://singletrackworld.com/forum/topic/which-power-meter-stages-or-power2max
I've been using Keo cleats with my P1s with no ill effects.
My Power2Max just works - I've had it a few years so I suspect my exact version is no longer available but no complaints.
Sweamrs single sided 4iiii also works - no idea about dual sided.
You've presumably read DCRainmaker's opinion('s) on all things power? Yes it's the web but he tries very hard to be unbiased etc and I've read some of his reviews where he's given a product a real beating.
If the timing was right I would be buying Kyrton57's Infocranks. I know quite a few people who run them and they are seemingly faultless.
2 x Power2maxs here, both been perfect for 2 years/1 year. They're the more recent type, one on a Rotor 3D crank, one on the cheap FSA one (for the winter bike).
Markets moved on and prices for full left & right means I wouldn't bother with a left crank or pedal based PM. For your budget I'd be looking at Power2Max or Quarq based purely on which you can get cheaper. Both are simple to fit, provide left and right power and just work. Quarq offer BLE support if that's important to you.
I've looked at the quarq elsa rs but I'll take a look at power2max but by changing the crank I may have to alter the bottom bracket.