Cool i own the 135 too and ordered the 16-35 last week. Hope it comes soon and i think these are two excellent pieces of glass!
Did you have the 2.8 or the 4 version?
I had the "base model" 70-200 haha...f4 non-IS. It was a great lens, but without IS on a crop body you really needed to watch the shutter speed or your keeper rate went way down. It's really a daylight lens with the bodies I was shooting with at the time (10D/20D/30D), which didn't have the low light capabilities today's cameras have. I sold that lens to buy the Tamron 70-300 VC USD and never regretted it. Sure, the Tamron may be slightly less sharp, but thanks to the VC my *OVERALL* keeper rate is much higher.
Which version (I or II) of the 16-35L did you buy? I love this lens...it's been glued to the front of my cameras for 99% of the shooting I do. I did a month-long backpacking trip through Europe last summer and took just one body and one lens (5D2/16-35L)...never felt like I needed more. A fast prime would have been nice for street shots, but other than that, the 16-35L did it all for me!