Ok, just finished the test game. Almost six hours was spent, but that includes lunch (at the beginning), quite a bit of explaining what everything on the character sheets meant, and we had the added “bonus” of two small children requiring constant attention as a side distraction. My own prep was decent; I had made a lot of notes to myself and even though there were some “let me look that up in the book” pauses now and then, things wen’t without too many interruptions. I felt a bit overwhelmed at times, but not too badly.
Overall, it both was and wasn’t a success. The scenario itself worked pretty well and we had a lot of fun twists, and we ended up with the cleric possessed and the rest trapped (perhaps permanently) in the crypt after a Flee conflict which the party lost. We decided to stop at that point; even though it wasn’t quite a total party kill (yet!), there was no easy way out and it was getting late – and besides, this was a test game.
The bad? The players didn’t much care for the rules. The main complaint was “way too many moving parts!”, with the opinion that the same sort of effect could have been gotten with a smaller and more cohesive ruleset – and yeah, I do see their point, the Burning Wheel baggage that comes to Torchbearer results in a ton of different and interlocking things to keep track off. While probably a good thing to people already familiar with BW, it’s not a positive factor otherwise. It’s quite valid to ask “do you really need skills, abilities, wises, traits, instinct, belief, goal, encumbrance rules, etc etc” as separate entities?", when the answer (as demonstrated by many other games) is “no, not really”.
I myself am ok with the complexity in TB, but I do understand the complaints.
One player said it was more a board game than a roleplaying game, and while I disagree with that I do understand where he’s coming from, TB contains a lot of rules which (quite artificially) restrict what you can and cannot do. Prime among these is the need-checks-for-recovery thing. While it’s valid from a gamist viewpoint, from a roleplayer viewpoint it can seem a bit silly (and yes, board game -like): you need to act in certain ways, possibly harmful to your character and the party, before you can try to make camp and heal. If you think of the game as a sort-of simulation, that’s a very valid complaint: it’s a totally artificial game mechanic, which doesn’t make much sense.
They also felt that the resource grind was too extreme. You might get thirsty and hungry again after just a few moments, and torches seemed to act more like matches (2 turns is a ridiculously short time, there). Yes, I understand that it’s “narrative time”, but still it results in situation where a torch only lasts a few minutes. I’m tempted to rule torches etc on a more freeform basis from now on, having them go out more based on real elapsed time.
That said, they did agree that all complicated rulesets need a bit of time, and that things might flow better now that they sort-of understand the resource management game. They suggested another game in a few weeks time, with the same (pregen) characters but in a different scenario. I of course agreed, we’ll see how it goes. 
At the moment, I’m undecided between finding some nice classic D&D module and (heavily) retooling some segment of it, or trying out the scenario in the main book.