John,
My primary LBS is nice and even kinda eager to hear about my experiences etc. They don't mind working on it at all, but they do complain about taking the wheels off (removing skewers) and they tend to fall back quite quickly on "I don't know" without thinking about the problem.
Case in point, right now I have a creaking/popping noise in my bottom bracket at starts or under heavy load (up hill). When I recreated it in the shop they listened to the bottom bracket and said it didn't sound like the bottom bracket but something else in the rest of "that crazy stuff" pointing to the carboyoke bottom bracket clamp etc.
While they may be right, undetermined at this point, they can be too quick to dismiss or too quick to not think about the standard problems in favor of "it must be something in that crazy stuff that I don't know about". They aren't really keen on thinking outside the box.
Other things:
They tend to ignore the placement of the dropout hanger on the rear derailer (set it up one way and then when/if they remove and re-install the wheel they let it pull forward and then the adjustment seems off.
Nobody there can ride the thing, therefore they can't road test any changes they make to the drive-train, new wheels, brake adjustments etc. That can lead to me having to come back to them 2-3 times for adjustments. I am, over time, just learning how to do it myself because it is just easier.
I have taken my bike to another local (to my office) shop when my rear derailer cable broke on the way to work. They are a boutique, hand-built frames, kinda shop with a lot of seniority in the Seattle area [cough]Davidson[cough] but I have found them to be snobbish about uprights and turn their noses up at recumbents (esp my previous bike).
When I retrieved my bike for the cable repair the owner helped me. I asked for "the recumbent with the broken derailer hanger". I misspoke. Derailer hanger just rolled off the tongue.
He retrieved my bike and inspected the derailer hanger closely for about 3 seconds, stood up and said "Yep, looks like a weak design."
When I explained I had misspoken and meant "the derailer cable" he just shrugged.
My regular LBS is more than willing to try things but I have to do a LOT of suggestion and like I said, I am just learning how to do most things myself.
I don't do hubs, wheels, or bottom bracket adjustments (yet) but I am going to do more and more of the rest of my own maintenance. Even though they are willing and mostly able, it really only extends to the owner and the head mechanic. The other guys only know mountain and BMX (that is the focus of the shop, to be fair) and don't really care to learn more than what I like about it, how comfy it is, etc. They don't really want to work on it and, likewise, I don't want them working on it.
That is all I can think of for now.
I REALLY wish that the (only) "local" bike shop that is recumbent oriented was worth a pile of rusty chains, but they aren't.
Down in Portland there is a great shop, Coventry Cycles. I would like to take my bike in there for an overhaul one day just to get their feedback.