Got my Alpinestars Jet Road Gore-Tex Glove and was able to make at least a fit comparison against my old Joe Rocket Rush winter gloves. By time I got the Alpinestars gloves, the really cold weather was past, so testing of warmth might have to wait until next year.
1st : I am usually a FirstGear equipment centered person.
The Joe Rocket gloves I got a few years back, after reading Paul's comments ( at newenough ) that they are not as thick as others, offering good feel of the controls. I used them for 2 years, until I got Gerbing G3 gloves when I ordered my heated kit. The JR rush glove started to feel like a bulky glove after a while of use, but that was due to not using them all the time ( there are 3 other seasons for riding I found out ). Much below 26*, the glove is useless unless it is a very short ride ( ~45 min ), but this is due to the thinner insulation ( which was the selling point of then at the time ).
The JR glove has the thumb squeegee device, which works well when the visor stays wet, but as all, once it starts to dry it is not worth trying ( smears rather then cleans ).
No knuckle protection, only some padding in the glove at the Ulna area, and the back of the glove ( not the knuckles ).
Cost : ~ USD$ 45.00
I got the Alpinestars Jet Road Gore-Tex Glove due to a review in Ride mag.
These have a bit more bulk to them, when compared to the JR rush gloves. Just a bit harder to make a fist with my 4th finger. The other 3 fingers and thumb conform to the fist test very well, so they are not boxing glove type feel. They have a knuckle protection on them, and from the Ride review, they do well under crash conditions ( one of the writers tested his ).
[EDIT : Add in some real use info ]
I got a chance the night of 6-APR to try out the cold weather usage. Out temp actual 30* F, wind chill ~ 21*. 2.5 hours ride In temp Actual temp 26*F, wind chill temp 14*F.
I was ok for about the first 1hr 45 min. After that I stopped for fuel, and put a pair of bicycle glove liners in. They had reached what I would consider the bottom usage temp. My fingers were really starting to get cold, and my hands were moving a bit slower then normal, and I was paying more attention to my cold fingers more and more often, then riding. Seems that the bottom side usage ( in my abilities ) for these is about 26 to 28*F, depending on the wind chill ( ~ 20 MPH winds ).
All in all, the JR gloves work great in the 40's and high 30's. The heated gloves for me are still the way to go. Extended drive time at 38*F these might be a better choice then the JR gloves ( 6+ hrs )
Cost : ~ USD$ 135.00.
Both have dual closures ( cuff and wrist )
I can only take the warmth feature compare as subjective at this point ( sorry I know part useless ) with the Gore-Tex lining in the Alpinestars gloves, and the additional thickness ( and Ride's review ) over the JR glove I think they would do much better in the 24* to 26* range. How low, I can't say at the moment, then again this is Chicago, I might be able to find out yet this year.

No fair comparing them to the Gerbing G3 gloves, those feel Spring glove thin with heat ( still waiting on a Warm and Safe compare, before I think of trying that )
Thought I'd offer up a fit compare. The temperature range is a subjective comparison, as people's comfort level is different. I am generally not a cold person, this might be why I can use the JR gloves to 29* for long rides, and 26* for shorter rides.
Logic behind spending heated glove price on unheated. I use heated gear for survival reason ( keep the body warm, and concentrate on riding, and to lengthen the riding season to a full 12 months in Chicago ), but I really don't care too much for the plugging in all the time. Just a personal thing I guess, but form always follows function.