I had a 1980 PE175 - it had first belonged to Geoff Fox of Fox suspensions and I got it practically brand new back in the day. Fun to ride, not much grunt, but I could fly on downhills with it - the chassis was very stable. You had to wring it out like a 125.
I had an 82 PE175 with the original Full-floater back end (that huge linkage assembly where neither end of the shock attached to the frame). As mentioned, not a powerhouse, but a really balanced overall bike. It was also absolutely bulletproof for me.
Downsides were mostly the weak brakes and it was kind of heavy for what it was.
Oh yeah, and I recall it had the oddest rear brake setup, where the brake pedal rotated a little axle that went through the middle of the swingarm and actuated another rod on the other side of the bike.
We are bike rich but dollar poor! Been thinning the heard lately. Sold off all of the YZs. I have a 75 TS400 thats going to get a minor resto this winter and hopefully move on down the road soon after. I think Im down to around 12 or 15, I lost count!