I tried out the Telex 850 in the CRJ (a 200, mind you, which is a lot quieter than a 700). I wanted desperately to like it for the reasons you specify, but it was just too loud. For you guys that don't think it's too loud, I'm a little concerned you may have suffered some hearing loss already.
After that I tried out the Sennheiser HMEC-25KA and liked it much better. It's a bit bulkier than the Telex, but due to the fact that it actually covers your ears, it provides sufficient noise reduction even if the batteries are dead. A set of two AAs lasts me about 6 full flying days. Obviously, you get better life with better batteries. In the end, the Sennheiser is what I bought. German engineering triumphs again.
For those of you wondering how I could afford it on a regional FOs salary, I got a fantastic deal during Sun-n-Fun (I didn't have to go personally) from an avionics shop down in FL. They sold me a "refurbished" headset, which means it was new, but an airshow demo. It was totally indistinguishable from new, though. Total price with the SkyWest discount and the Sun-n-Fun rebate was about $325. Try
www.aviation-headset.com and see if they're running any deals. I'm not affiliated with them in any way, so I see nothing wrong with offering a reference here.
One word of advice: TRY BEFORE YOU BUY!!
By the way, the reason I ended up having to get a new headset is because I was getting interference between my David Clarkes and the windshield heat. It cause a continuous hum on the intercom that got louder if I turned my head a certain way or moved closer to the windows.