I've spent the evening exploring part of the starter dungeon for the core rules with a fighter I rolled up and have been playing with my revised rules, including the mods to character attributes. Oh my goodness does this feel old school. He's running from monsters, hiding behind doors, getting jumped by random encounters, climbing into little alcoves, making INT checks to map correctly... he just needs a 10' pole and he'd be the most old school dungeon crawler ever.
I LOVE the changes to attributes. Now, I am playing a viable fighter who doesn't have over the top attributes. It doesn't really matter that much. He failed a STR check to force a door (by 1 point), so that higher STR would have helped there, but that's been it. I LOVE the rules for fighting with sword and shield. Fights feel messy and dirty, as he's swinging (and repeatedly dropping) his sword and trying to shield bash skeletons to dust. I got very lucky (literally rolled 15 twice on a D30 potion chart) to get 2 greater potions of healing, which he had to drink both of just to survive. The XP are coming slow, and the treasure is small (but appropriate). Treasure no longer gives XP, so I have to keep killing monsters if I want to get XP. And I do. I really do.
The temptation to pick up a level of thief once I hit 2 is going to overwhelming (it will be SO helpful for solo dungeon crawling), and I might need lore at some point just to keep up with all the magic items I'm finding, but this has been fun.
If I was to tie XP to treasure (1 gold = 1 XP), I'd have picked up another 12 XP in addition to the 14 XP from monsters. That seems reasonable. I house rule that back in, which means that it is literally back in the rules - so it goes from house rule to official rule instantly.
The next thing is going to be to pick up a retainer of some kind. It would be cool to have a goblin or kobold who follows him around... hmm...