I'll give you my take on the issue of dealers vs. independents.

I have worked at factory M/b dealerships and got tired of the games as a technician so I started my own mobile service here in Atlanta on M/b's only.

The dealer techs work their butts of trying to turn flat rate hours.
Some techs are great and very professional, others are complete hacks and cut corners to turn hours.

Some local dealerships here are very good about getting your warranty work covered when you bring your car in under warranty, and others dealers will not touch anything uless you complain about it.

I refer my customers under warranty to the shop that will best suit their needs for factory warranty work when their car is ready to go out of warranty.
Everybody wins with this deal right?
Wrong!
Some dealers, no names, think that it is an abuse of Mercedes benz credit card to make repairs under warranty that the customer does not complain about.
This sucks for the customer and the technician trying to make his 40 hour minimum for the week.
I noticed that the last shop I worked at went to this policy under new management and technicians that usually turned 100 plus hours in a week on flat rate wre now lucky to turn 40 hours, and technicians started leaving in droves, new ,young techs were hired for much less pay and the owners were happy since the big pay veterans were now gone.
Now the dealer has a bunch of kids practicing on their vehicles and the veterans that are now left become large suck ups and become shop foremans to school the kids, customer service goes down the toilet and the place is a big, high priced day care center for new techs.
The veterans have no choice but to leave for greener pastures at another dealership that is not afraid to fix cars or do warranty repairs to make their customers happy.

Independents.
There are good ones and bad ones.
Good ones are usually the ones that have been around for a while, but some new ones are great as well, they just don't have their name out there much yet, but reputation and referrals will make them better as time goes by.

Treating customers right and being reasonably priced will always get return business.
I, being a mobile tech am limited to work I can do obviously, and I refer customers for engine work and such to independents and factory delaerships depending on their needs.

My biggest problem is that I have no control of what that guy does to the customer I send them.
I was sending alot of work to one guy and my customers were happy with his work, but I always check up on them after I send them somewhere.
I noticed one customer was sent to a guy that charged him over $600.00 for some transmission work, so I go over to see the customer a week later for some scheduled service and I find out the transmission pan was never even pulled and the original gasket was still there.
No tool marks on the pan bolts and residial fluid that was just wiped off poorly with a rag.
Do I send people back to that guy ? No!
Are there still people that love this guy because he has treated them right? Yes!
This is the kind of work ethic that will bite you in the butt hard if caught.
it is just not worth getting greedy and taking advantage of customers.

This puts my reputation on the line as well so that's why I always follow up and inspect work done by someone I refer a customer to.

I personally, always do what I say I'm going to do and treat customers more fairly than most since it's my reputation on the line.

You can't make everyone happy all the time because not all customers are the same, but for the most part, if you go above and beyond, you should do well.
One of the biggest problems I have with customers is honesty.
Remember, it goes both ways.
Everyone wants an honest shop to go to, but one thing that is overlooked sometimes is customer honesty.
Customers can bring in their car to the shop with known problems they have had for years and bring it in for something unrelated, then blame the shop for "creating" theese problems that they may have had patched up cheaply at another shop or by themselves.

This is one reason why I pick and choose the jobs I perform and the people I deal with.
Nobody likes dishonest shops taking advantage of them, and shops do not like being taken advantage of by dishonest customers.

I am always looking for good independent shops in Atlanta to send locals to for repairs beyond my scope due to my mobility.
I just expect those shops to be honest and do what they say they are going to do.
This attitude will keep them in business longer than the rip off artist.