Shimano MTB Power Meter | Stages or XCadey

[GSoroos]

My current mountain bike has a M785 2x crank. I found a deal on a Stages M8000 left side power meter and have been riding that for about 2 years. On my road bike I have the Magene PES P505 crankset and very happy with that.

Probably going to get a new MTB that has M8100 cranks, so I can't bring over the M8000 crank arm. Not a big deal, I'm keeping my old bike so I'll keep the power meter on it. But I want to get a power meter for the new one, and I don't want to spend a ton for it. My thoughts are as follows:
Stages M8100 left arm – I already have a stages power meter on my current bike so am familiar with the app, pairing and how it measures one side only. On sale it's under $300.
XCADEY Xpower M8100 crankset from Anrancee on AliEx ( https://www.aliexpress.us/item/3256807825790459.html ) – Spider based, so measurement on "both sides." And since it replaces the standard M8100 spider with the power meter spider, I can get replacement 104bcd round chainrings for much less than M8100 chainrings. On sale with coupons and coins it comes out to about $310. As a bonus since it's a full crankset, I could potentially sell the OEM XT crankset and recoup a few bucks to spend on something else.

I'm looking for thoughts on what others would do. Are there other options in that price range that wouldn't require swapping something else out (like bottom bracket, etc) Pedal based power seems to be a couple hundred more for a single side. Sigeyi spider for Shimano MTB is about $450 (plus a chainring and bolts)

[SunnyShore]

I know XCADEY gets a fairly decent feedback online, but I've had a bad experience a few years ago with one of their cadence sensor: it was slightly slower at calculating than the Garmin one I bought after, it was consuming the CR2032 batteries abnormally, and it died after a few months, not really a good experience lol.

Sigeyi is slightly more trustable, I've never used it personally but a couple friends had them on their road bikes and were satisfied with them.

Within the European market, I can also give good feedback to InPeak (polish brand, also used to sponsor Wilier Vittoria a few years ago iirc).
I had their left crank only option in the XT version.

I'll get slightly off topic but in my opinion the absolute best option in the MTB market are the pedal based power meter. It costs more but you'll have peace of mind that it'll work with any type bike or crankset. Otherwise you'll always have to swap out parts or be conditioned by the PM compatibility.

[GSoroos]

Thanks for your input. Appreciate it. Pedal based does seem like the most universal. Definitely giving them some consideration.

[bremerradkurier]

4iii also offers Airtag functionality in their crank based powermeters.

[GSoroos]

4iii also offers Airtag functionality in their crank based powermeters.

ooh?! Nice. Appreciate that info. Adding 4iii to the possibility as well. Price is similar to Stages too!