Here's my (long) tint story, hope it helps. (I have a '06 black wrx, for reference):
I went to D&L (in towson since that's where I live). Its somewhat new, but my neighbor had his civic done there and it looked good. Another friend of mine with a '04 WRX had his done at the white marsh location, but had to replace his windshield and had the front redone at the towson location. So that was enough for me, so I went with the 3M (which is definitely one of the best if not the best) and 35% (which is the legal limit in MD, they will do whatever you want though).
That 1st time it was pretty quick (particuraly the sale... they were ready to start right away ) but the work (all 4 windows, the back windsheild and the bar across the front) didn't take to long and seemed good. They even asked me about removing things like the "symmetric AWD" decal under the brake light, etc. which I thought was good attention to detail. I was happy with the service and they charged me for 20% tint which was very cool and I like the lifetime warranty (about $320 all-in-all) I took it home waited a week before opening the windows or removing the 3M print. There were a few spots that didn't look quite right to me (granted at that time I knew nothing of tint), so I called and they said to bring it in.
In particular, i had a large cluster of very small (but numerous enough to bend light and warp my view) spots right in my line of sight of my driver's side view mirror. I also had a glaring bright white chunk in the middle of my front passenger side window. Finally there were a few large bubbles (about the size of my pinky) around the bottom edges in the back windsheild. These were the big issues.
The 2nd time I brought it in, they looked at it and said some spots were problems, but it should settle/it was very humid/sometimes fuzz gets trapped/etc. So they said wait 3 days and bring it back in if they didn't go away. I waited a week or so and not only were they still there, but the back windows had developed several of the same "cluster" of small bubbles. If you drew a circle around each cluster, it would have been about 2 inches in diameter. So I went back. (At thie point I had started documenting everything, since i'm paranoid about getting screwed)
The 3rd time I brought it in they guys who did the work said they would replace it, but there will always be some spots (not comforting for someone who has never dealt with tint before). They took it around back and replaced the back 2 windows (not the ones I had complained about) and then came to get me. I went back and met the manager (not the owner, and not a worker I had seen there before) and he went on about tint settling/it's never perfect/etc. and they were going to puncture/hammer out some of the spots. Within 3 minutes of this, they pulled my car out and told me to go home. I asked, and was told the same "wait 3 days" and it should be fine. At this point the back windshield was fixed and looked great, the same with the 2 back ones they replace. However the front ones (which were the reason I brought it back in the first place), were getting worse. I think once I spoke with the guy I hadn't seen before, they just stopped working on it.
I waited about 2 weeks and then brought it in again (trip #4), this time I spoke with an older gentleman (might have been the owner?) who was great. He answered all my questions and said the brighter spots definitely needed replacing and the other ones should be done too, since they were right in my line of sight. I felt rejuvenated with customer satisfaction. So the next day I went in to have the work done, they replaced the front two windows quickly and finally on this 4th time the initial spots were gone and everything looked great. Its been about 3-4 weeks and i'm convinced its fine now.
I want to be clear that I think it was atypical (maybe a bad batch of tint, or something else went wrong that first time, seems to be my luck with such things). The people who worked there weren't rude or anything and they honored their work/warranty very well. But it was very inconvenient to have to bring it in 4 times and by the 3rd time, I did get worried for while about getting the run-around and paying a fair amount of cash to be annoyed everytime I look out the window.
The end result was a good price (with the lifetime garuntee) on an excellent tint job. I'd recommend the White Marsh location until the towson one gets off the ground a little more. It seemed to vary depending on who was working when I brought it in (The guy who was the most helpful normally worked at white marsh on the WRX/STI's, he did great work and personally apologized for all the trouble, which was appreciated). He, the owner's son, the owner?/older gentlemen, and the guy I spoke to when I first walked in the door on day one, were all very good. But sometimes when a new location opens up it can be hit or miss for a while (I overheard some discussions, to put it politely, amongst the staff to this effect). I would definitely recommend D&L in general and hope/think that I was just an unfortunate statistical anomaly.
As a side note, I brought them all a dozen doughnuts the last time I went. It seemed to work well