The experience you get from the LBS is most definitely a modifier in anyone's perception of one brand or another. There's no way to avoid that, but I would think that more often than not, the level of service you receive from the people at the shop is independent of the brands they sell.
I've walked into my local shop on random days and have gotten Godlike service and attention on one day, spotty the next and downright no service on yet another occasion, and this is from the same people each time.
People have up days and down days and I try to factor that into every interaction I have with people. Heck, without my Job I would be homeless, but even with that level of importance and responsibility, I still have days where I have to bite my tongue to keep from saying something REALLY abrasive that might lose me my job... So the argument that "They're being paid to be nice and attentive so they should be that way 100% of the time" is more a guideline then a rule 🙂
Maybe they had a really difficult customer a few minutes prior, and they were trying to decompress who knows?
All I know is that if they gave me crappy service every single time I was in there, then it would be a no brainer... But since they are great, most of the time, I figure I'm good to go.
As far as brands of bikes Giant or Trek, I always get prompt courteous replies to all the emails I send to Trek, and even had one Trek Representative go out of her way to send me extra info email when she clearly didn't have to.
I have had no issues with my Trek, and if you think about it, isn't that the best customer service of all? I rode exactly 7 different bikes during the shopping months and some three or four times. All of them were in the 3-4k range and I'm convinced that when you're in that spending range it would be pretty difficult to make a really bad choice quality wise (sizing wise is a different story)
The thing that sold me on my LBS was that the owner said that the Specialized I tried actually fit me slightly better according to the numbers and my fitting on the fit cycle even though the Trek still felt more comfortable to me while riding...
His advice was to play it safe and maximize my enjoyment of cycling while minimizing the chance for discomfort or even injury and go with the Specialized which was more than $1000.00 less... I was convinced that day that the guy was sincere, and even though I ended up getting the Trek, and I've still had "not so great experiences" with their service on rare occasions, I see those as honest guys on a bad day, like I have bad days, and not an indication of overall service or intentions... and even less on the brands they carry.
Oh, and they did mention (the shop people) that all of their brands service were great, and they rarely had problems with any legitimate request or claim...
The general attitude of the LBS is very important, but never let it sway you from the right bike choice, just the right seller choice... Trek and Giant are brands, not sales, that's something to also keep in mind...
Have a good one!
Feanor