If you buy PO32, you should buy Microtonic. It expands it into a really amazing and versatile drum machine. It’s a fantastic combination and well worth the money. It would be too limiting without it, IMHO.
I just bought PO33 and 35 yesterday. I need to spend more time with them, but my first impression is that PO32 + Microtonic is still the strongest PO and also one of my favorite drum machines of all time.
The initial problem I see with PO33 is that each pattern is only one bar, so you can’t readily loop a phrase more than one bar. It’s still awesome though and I can’t wait to explore it more. The PO33 and PO32 + MT are probably the coolest combination, although the PO35 could turn out to be a surprise powerhouse once I spend more time with it.