nylon and metal slides

Yes, in my experience the 91-001P and 91-033P are very similar. The only major difference is in the size of the front tip, but that may or may not matter depending on what kind of window you're working with. You'll have to check the size of the front tip on your original to verify.

Other than that, there is a tradeoff: you lose strength with the nylon latches and in time they will eventually break sooner than the metal latches would have.

Sounds good! We appreciate your consideration. 

Please let me know if you had any other questions and I will do my best to assist you.