Last year's Under Armour Heat Gear Sonic Long Sleeve Shirts were definitely a five star product. However, I think this year's model is not as good.
To be absolutely clear, in my opinion this is still probably the best compression shirt available on the market. In this area, Under Armour is still outpacing other brands like Nike by a *long* shot. The shirts are true compression, the materials wicks sweat really well, the size and cut are good, and the raglan sleeve style looks a lot nicer than standard sleeves.
I dropped a few stars however, because I feel like this is a case of trying to fix a product that isn't broken. Last year's line was perfect and none of the changes in this year's line are improvements. There seem to be two major changes:
1) Contrast color stitching was added as a design element:
The old shirts were all one solid color, whereas these shirts have weird lines of brightly colored stitches running down the sides, chest and inside of the arms. This is pretty annoying because most other lines of Under Armour compression shirts have gone the direction of gaudy designs and patterns (I'm an adult so I don't want to look like a superhero, walking UA billboard, or pretend soldier). The major appeal of this line has been the clean and neat look. These shirts were originally meant to be a functional base layer, so I'd prefer to keep them looking this way. The extra ornamentation is unnecessary and even distracting when you pair them with parts of another uniform with its own design pattern.
2) A different more mesh like material is used on the inside and underside of the arms:
I guess the idea here was that this material would make these areas more breathable and less restrictive. It's a good idea in theory, and it might do that, but I don't really notice. What I do notice is that it compromises the compression of the shirt in and around these areas. Particularly after you've started sweating. It also makes the shirt just feel more 'substantial'. Which is not a good thing, since the shirt should feel like a second skin. In short, the trade off isn't worth it.
3) Ok, I only said two, but I also prefer the neckline from last year's model, this one feels too big.
To repeat though, these are probably still the best compression shirts on the market. I've tried a good amount of brands and haven't encountered anything that comes close.
For anyone curious about sizing, I am 5'11.5" and 157 lb. I have a slender muscular build with significant tapering from shoulders to waist. I prefer a very tight fit and wear a Small. I used to wear a medium but I noticed that after 3 washes, these shirts tend to loosen up slightly (you won't notice when you first put them on, but after you start sweating post-3rd wash you'll notice). So a used small ends up fitting like a brand new medium when actually in use. If you're my size, Small is the way to go for real compression and Medium is good if you prefer something slightly more comfortable and easier to put on. In either case the arm length and torso length seem fine.
Oh yeah, also I wash these in cold and line dry, but I've thrown them in a dryer on high before and they didn't shrink.