I have used the DriDucks, an AGG sil rain jacket and currently using the Luke's UltraLite rain jacket. I also have the GoLite Tumalo (but the prior version, made from Pertex Shield).
In my opinion, in order of breathability, from most to the least, it would be something like this:
AGG/Luke's sil jacket
In terms of both cost & durability, from most to least, it would go like this:
AGG/Luke's Sil jacket
The Tumalo is a great jacket, but in the end, the weight of these other jackets made me decide to leave the Tumalo behind.
I had been using the DriDucks for a while, and they have been great. Lightweight, inexpensive, but not very durable at all, however, if you don't wear them often, they should last a while. And if not, then duct tape will fix them right up! They are fairly breathable, but even when active, it can still get a little wet inside the shell. To be honest, I have never really minded this though...
Which brings me to the sil jackets. I have choosen these because they are even lighter than the DriDucks, and more durable. The trade off is breathability.
As had been mentioned, silnylon will not breathe, at all. Don't even think that it will, cause it won't. Because of this, it will block every bit of wind that comes at you (to an extent I would imagine). However, as has been mentioned, a windshirt is generally breathable, so as far as rain shell and a windshirt, I guess it depends on what you are after...
Also, as has been mentioned, silnylon can create a bit of a microclimate beneath it's shell, especially when active. So, here again, this will depend on the user. Me personally, even while hiking, I can still open the pit zips, and lower the front zip a bit and this is fine for me. Not perfect, but I am ok with it.
I started with the AGG jacket. George was lots of help when I asked about sizing. He even took pics of himself and emailed them to me. I got the XL which was a bit boxy feeling, but allowed for plenty of room for layers underneath, as well as some wind to blow through. My version did not have pit zips. However, there were some things I was not super happy about, particularly the sleeve length, which was short. As well, I did not like the front zip, or the storm flap. I removed the velcro tabs from the wrist cuffs and installed a cord & cord lock, which worked better, but not the best.
Meanwhile, I came across Luke's Ultralite sil jacket. I called him and found out I could get some custom work, as in request for longer than normal sleeves. (To be fair, AGG may have done this, but when I got it, I did not ask.) Also, he uses a waterproof zipper on the front, which I like better than the AGG model. He also had pit zips as an option (AGG did not when I got mine.) He also put a better wrist cuff cord lock closure system on it. And, as a bonus, after receiving it, I realized that the fit of hood on the Luke's UL was way better. It could be adjusted front to back, and along the sides of the face. Not to mention, I got mine in black! (Which will probably create more of a microclimate under the shell... I dunno.)
Anyway, I have only used the Lukes jacket once now, and it worked as I expected. The inside of the hood was wet after hiking in it for about an hour and a half or so, but I'm not sure how much was due to sweat since I was pulling the hood on and off at times. Either way, at this point, I am quite happy with it. It fits me as I want it too, which is a big plus for me. It is light, and IMO, considerably durable. And it gets the job done...
If you are interested, here is a better look at it:
In my opinion, I think a silnylon rain shell is a good enough option, but it really depends on your needs and expectations.