​​​​​​If money was really tight I could probably get away with careful rear loading and a new rear tire, I guess.

It's the 615 GT.

Yes, there's something weirdly buttery about the bike in general that I like, but maybe the tires are contributing to the lack of confident feelings in cornering or under load at speed. Like I said, things definitely improved after I went up to 90 PSI, and could no longer make the sidewalls near the ground wiggle like an aspic.