I compared this lens to sooo many others before nervously hitting the buy button. Wow, so glad I did. I friggin LOVE this lens! The price is justified for the results.
I was looking for a lens that can do double duty (portrait and products) and I found a winner!
1) Incredibly sharp! I mean sharp. So sharp that I've exported numerous images without realizing that I didn't touch the sharpening slider. I've been doing some street photography with it and even from a distance away I can still see the pores and cracks on people's skin. Crazy.
2) The color and contrast straight out the camera (in RAW) already pops. Seriously, with portraits at f/2.8 & f/4 look almost 3D.
3) The IS. I've been developing a shake in my hands so with a focal length of this size is a must. The IS does not let you down. Works instantly. The IS & AF does make an audible sound. The sound isn't terrible but the person sitting next to you in a quiet room may here it.
4) at 2.8 there's vignetting. obvious undeniable strong vignetting. BUT for my style, I love it! Plus with one click it's gone.
5) Fringing/CA. Handled incredibly well even at 2.8. If you set a import preset in LR for Remove Chromatic Aberration any that may have appeared is gone. I had the canon 85mm 1.8 and HATED the fringing/CA. Horrible! So many ruined pics. Not with this one.
6) Auto Focus. The auto focus isn't nearly as fast as the 85mm 1.8 but not many lenses are. It's not a sports lens at all (find another lens for that) but for the street, portraits, products, and family stuff I've shot it's done me good. Low light performance AF could be a lot better. You can make it work but you're going to miss focus on some shots. I wouldn't recommend this for extremely low light concerts where the performers move around a lot. For other types of low light it should be cool. The focus limiter is a champ and highly recommend learning to use it. It will save you from some missed shots.
7) Yeah it's plastic. So what. It's definitely not even close to being cheaply built like the 50mm 1.8. It's quality and should stand up.
Anyone in doubt about this being good for portraits, don't be. It's incredible. Just know that you're going to be doing some skin retouching to knock down some of the detail this beast can capture.
All the following were shot at f/2.8 and in high contrast light
No sharpening done on these (other the 25 default that lightroom imports all images with) The reflection in his glasses are mirrored from across the street and you can still make out the details.


Tonal and Contrast Adjustments, B&W conversion, Still No Sharpening:Here are others that have been done in my very over
processed style of development don't fault the lens for that.