@v1nce - the rack has the triangles so panniers won't foul the rear wheels. It is an all aluminum rack and not very heavy. It spreads out the load quite a bit on the seatpost.
Here is a link to the rack at on the Performance Bike website:
http://www.performancebike.com/shop/...tegory_ID=2325
I personally have had no issue with this rack on my other bikes and if you think it high, compared to my body mass it is quite low. Also 20 pounds on the rack compared to my 220lbs is nothing. This is also the reason I went with heavy duty rims and upgraded my components. Peter felt the frame would be absolutely no issue and I feel no flexing at all. My seat post is bottomed out in the frame so it spreads the load all down the seatpost tube.
The rack itself doesn't way much at all. All together the bike (without bag but with rack and lights and the Thubuster) is at 29.4 lbs. The rack stays there as solid as can be. No vibration and I carried my 70lb daughter on this rack on another bike for several miles with no ill effects. It is quite sturdy and has 4 screws clamping it on the post.
They also make this rack in QR version without the pannier stays:
http://www.performancebike.com/shop/....cfm?SKU=19328
I can easily lower the rack another inch or so but I like the panniers to stay well clear of my size 47-48 (Euro size) feet or 13 in US. Too much lower and my heels kick the panniers at times. As I mentioned earlier I also have it more rearward which makes it look bigger too. It will also double as a decent fender if you don't have one on the rear.
Today I went shopping with my kids and had it pretty well loaded up and it was fine even going across rain slickened roads, snow and ice. This bike is really amazing. Finally the Brooks is starting to loosen up too and adapt to my nether bits. So you could buy the rack without the pannier stays but I like them and tried to find a rack like this so if I didn't have fenders OR I mounted it high to clear my feet, the bags wouldn't hit the rear wheel. Hopefully it is more understandable now.