I think generally in-person shopping is quite a lot better for me, except in places like Nordstrom, where I've never bought anything, even though I like to browse. I find it too confusing. IMaybe I just need to get to know what brands I like.
I find BR, CM, and JCrew kind of fun in person, but I wouldn't buy anything from them online due to the discrepancies in quality from one thing to another.
I really like boutiques in person. The owners are more mature, invested, and less busy (and the shops themselves have better lighting, now that I think about it). And of course, the products are more interesting. I just enjoy the whole experience so much more, and have had 100% success.
For online, I find the little videos of the person walking in the garment REALLY helpful.
ETA: It's funny because I never really think I'm getting gypped in person, even though I'm a bit of a bargain hunter.