What did you find to be better than expected?

[Disappointed_Horse]

I agree, Takumars proved to be much better than I expected. Pentax-m lenses too.
I use Nikon most of the time, that is because their cameras just work well and the lenses do the job. But I think Zuiko and Takumars are better than I initially thought.

I only have one K-mount lens, which is a 50mm f/2 SMC Pentax M that came with my K1000. It's an excellent performer as well.

I do slightly prefer my Nikon cameras to my Pentaxs—the viewfinders are a bit bigger and brighter, and agree with my eyes a bit more. I'm also not as keen on the K-mount models other than the K1000, KM, and KX, and the KM and KX were only produced for a few years. The Nikons I like (the FE/FM series, F, and F2) had longer production runs and while I don't think either the KM or KX are particularly hard to find, there are a lot more of the Nikons out there. But if I hadn't alreay bought into the Nikon system, I would be perfectly happy to stay with Pentax.

I had an OM-1MD for a while and liked it too, but it needed service and I figured I was already invested in F, M42, and K mount, so adding another mount wouldn't make much sense. I ended up selling the OM-1

 

[das]

The list is long. But some my favorites that were so much better than I would have expected, given the internet noise:

Bessa R4 series: Probably the best wide angle film RF platform ever.
Konica 50mm f/1.9 and 50mm f/3.5: Old 1950s M39 lenses never sold in the North American market that are both world class.
Carl Zeiss Jena 200mm f/2.8 (M42), 25mm f/4 Flektogon (M42), and 50mm f/1.4 (PB Mount): Under-appreciated, top-tier of the era film lenses.
Zeiss 35mm f/3.4 Skoparex (M42 / Icarex Bayonet): Voigtlander-designed, one of the best 35mm focal length SLR lenses of the pre-ASPH era.
Nikon 35mm f/2.5 S Mount: Almost the equal of the f/2.8 Summaron.
Konica 21-35mm f/3.4-4 Dual Hexanon: Fantastic at both focal lengths. An OG Tri-Elmar killer.