I've only ever had my ears gunned at Claire's, so I can't compare HTC to any other piercing place, but I can say I was really happy with my experience.
After reading reviews on Yelp all day at work, I decided that I was going to drive like a maniac over to HTC as soon as I clocked out to get my piercing done and over with. I walked in 15 minutes before closing, shivering with excitement/fear/adrenaline/cold. There was only a single piercer (Peck) and the counter guy there and they were really nice and professional even though they probably wanted to go home. It was really clean and Peck talked me through everything- he freehanded the piercing and it was over before I knew it! I spent more time filling out the paperwork than getting pierced. Went home with a salt-water mouthwash and adrenaline high, piercing healed perfectly.
I haven't bought any jewelry from them besides the surgical-grade titanium that they put in initially, so I can't say anything on those besides they're all really pretty. I'm planning on going back for all future piercings, that's for sure.