It's Arc'teryx! What more can you ask for?
I wanted to get the Theta AR (AR stands for "All Round" aka versatile) because I wanted more coverage than my Marmot Minimalist and because the Pro Shell breathes a lot better than Paclite (and it's Arc'teryx). Since the Theta is a relaxed fit jacket, it tends to run bigger than my athletic fit Arc'teryx coats. I am 5'3", 120 lbs. and I usually wear a size small. I ordered a small and my initial thought was that it was a bit bigger than I had wanted it to be. For a couple weeks, I was in limbo if I should exchange it for an x-small. Everyone said it looked fine but I didn't want the extra material to drag me down when I'm biking or hiking. This is what it comes down to: What are you going to use this coat for? If you're anything like me, you want something versatile; especially if you are going to spend this much money. If you plan to just use this jacket for warmer weather and don't intend to wear multiple layers underneath it, go for a size smaller than what you normally wear. If you plan to wear it during the colder months and intend to wear multiple layers underneath it, go for your normal size. I kept my size small and figured it was better to have it a bit bigger than a bit smaller. It is also a longer length jacket; it goes past my bum (it's really good for biking in the rain). Lastly, the craftsmanship is phenomenal! I am a huge Arc'teryx junkie and there is nothing out there that can steal my heart away from this company. If you are thinking about buying the Theta AR, I say go for it! You'll be happy you did and wished you would have done it sooner! I'm in love with mine!

PERFECT!!
I REALLY LIKE THIS JACKET, IT IS VERY LIGHT AND COMFORTABLE.

Arc'teryx, the Armani of Gore-Tex
We bought two of these jackets and got them for an good price we think. The jackets fit perfectly. I am 186cm and slim, she is 177cm and slim. We went for medium and small. The jackets are light weight, roomy and tight at the same time. The arms are long enough and the hood is big enough for a helmet. Everything is well thought out and it feels and looks like... the Armani of Gore-Tex. We have only tried them in days of heavy rain so far, but they have kept us completely dry. And they breath very well. Very happy. Can't wait for winter. We also bought some Arc'teryx pants on sale. Same thing. Great poducts, great value. We could maybe wish for a snow skirt, but with tall pants that should not be a problem. The jackets have great tightening features around hips and waist. The pockets are not the largest I've seen, but big enough. I don't think you can go wrong with these jackets :)

Amazing!
I just bought this jacket and was recently caught in a downpour. I was completely dry thanks to this jacket. Love the style and fit, too.

Great Great jacket.
Took it with on a skiing trip to norway.