125-200cc Shock Differences

I’m working on my 09 wr165. I’ve pulled the suspension off for servicing and I got looking at the rear shock. I also have a rear shock off an 08 te250. These shocks seem the same and the te shock fits in the wr. The difference is that the te shock has a longer reservoir. Would this make it a better shock, having more reservoir space.
Both are Sachs shocks.
Just looking to put in the best of the two shocks.
Any input would be appreciated.

Thx
K

Clearance is the biggest issue, Yes it will fit but you will have to tweek the pipe to get the stinger to clear the bigger reservoir.
And if my memory is correct the angle that the reservoir leaves the shock body is different on some of the 4 banger items.

Yes. I’m sure I can get it to fit. Question is is it worth it? Is the TE shock better?

Since they're the same era I wouldn't expect the TE shock to be better in general. You may like it better though. If it's stock probably different spring rate and valving.
I would hope the 165 shock works better on the 165 and TE shock works better on the TE

Somewhere around those years (sorry I don't remember) the Sachs shock upgraded to a having a check-valve in the "rebound" damping circuit. That's a magnificent upgrade, IMO, so if the 09 shock has that then build off that one. If not, then neither has an advantage when tuned to its best.