I owned a string of PE 175's. N, T & Z. My bro had an X. They were awesome enduro bikes in their day and with a good rider could beat anything else - IT175, XR (any capacity), KDX. You had to rev them to get them on the boil though and charge hills hard. Maintenance was easy and they were reliable. Change the rings frequently to keep it fresh.
I always thought the best PE would be the Z with an X motor. The X was the best combination of top end and bottom end in my view. The 400 was really fun in the open but the 175 would kill it in the tight stuff in the bush. Never rode a 250 so cant comment.
Aftermarket shocks would be an improvement though I never bothered (couldnt afford it) as I rode in the NZ bush mainly. I would own one again. They wouldnt be competitive in 250 evo VMX however