I almost never go purist - the Bet on Boss prep might as well be a Token as far as I'm concerned.
However, the either nothing or prepped to the gills thing is not really my style (I'd be curious to hear what sidestepper does
I sort of always casually prep enough to destroy pretty much anything wihout thinking about it because there are gods in the game that come with no real disadvatages to prepping them. And if I'm looking for gold, I'm doing the only compromise between the game and me in letting the game choose where I go by picking up either the PQI or the Flaming run. Then for most of the sub vicious stuff, unless I feel like it, I either prep components for a combo I want to try out, a hard counter for any annoying PQI restriction (say a screwy class/badge), any of the "no penalty" utility gods (Binlor for mazes, Mystera or EM for spellcaster, GG because why not, don't necessarily take advantage of them at all), or just some utility or Bet on Boss.
Runs I really want to speed through just for the gold / completion, I go Codex + EM.
If this looks retarded, keep in mind that I generally see the runs as either "speed through", "try weird stuff out" or "challenge". First category I prep just enough to be guaranteed the paycheck but don't see anything I want to think about too hard, second category I go weird combos and untested stuff + backup overpowered utility god for paycheck, and third category is vicious PQI and VVGT where I either underprep on purpose or go full retarded but it's actually difficult.
And preping one random bit of cheeze has historically given me great opportunities to try risky stuff most other pro's wouldn't touch with a 10 foot pole
Drac halfling CP monsters FTW
(Though, if the game actually was balanced in certain regards, I'm not sure I'd be doing well at it, really...)