My first DSLR was Pentax K100D. I was considering Canon and Nikon counterparts. Canon was "too plastic", Nikon had a very dark viewfinder so I picked Pentax.
Next thing I bought was used Tamron 28-300 which I'm going to sell now. After upgrading to K-S2 more than year ago and buying M50/f1.7 and plastic fantastic 35mm/2.4 I recently bought Tamron 70-200/2.8
I'm happy with my gear and don't think I really need anything more. Maybe some 18-50 with wide aperture... But with my kit lenses and bright 35 I'm not missing anything right now
For me, Pentax was the only DSLR I afforded that had a viewfinder bright enough to play with manual focusing. Once I got used to Pentax I don't plan to change the system. Not only because of tight budget, but mostly of the ergonomy and features. And the image quality of course. I see no value in switching to any other brand. Things that done people say are not available for Pentax are mostly too expensive for me either way