[Rover]

Low(ish) weight makes it interesting. No IS, but that is not that important at these focal lengths anyway, if the price is right.

I beg to differ - I think the IS is great to have on my Canon 16-35/4 L lens. It has certainly broadened the scopes. I missed it when I had to switch to the 17-40/4 L for a few days - just as the Murphy's law would have it I had to go on another night creepin' job where the 17-40 showed itself... not good, to put it mildly. Through "sprayin' and prayin'" I was able to scrounge a few usable shots (erasing more than 150 along the way) whereas the 16-35 would get me through this without too much effort. I'm glad to have it back.

Looks like the new products just keep coming, innit?
https://photorumors.com/2018/08/01/new-tamron-17-35mm-f-2-8-4-di-osd-lens-model-a037-to-be-announced-soon/
The lens looks damn sexy. Not sure why they're so bent on reproducing the stats of their older (if very popular lenses) - they created the 28-75/2.8 and now this thing.

I'm sure I'm not going to give up my Canon 16-35/4.0 IS for this but I'm ready to recommend it to anyone, especially the owners of the Canon 17-40.

So is that any different from the old T17-35?

The motor, the weather sealing, the design - especially the design, all the new Tamrons look damn sexy to me.
The block diagram is also different so the performance should not be the same - with a little hope one can say that it's going to be better. Logically, it should. Looks like this lens is going to slot beneath the 15-30 in the lineup, offering compact size, the usage of filters and, most importantly, lower price.

For you the usage is different, of course. 22-46mm f3.6-5.2 FF equivalent because of your 1.3x crop body, and a workhorse lens. That is a tad different than a real UWA zoom for FF format.

Sorry, I don't understand your point (and no, I don't really care much what this lens, or any lens, is "equivalent" to in FF, miniMF, Four Thirds or any other format I'm not using ). I don't plan to get this Tamron anyway because I have the Canon 16-35/4 and do not intend to swap it out for anything else - it works very well on both formats I'm using (though the APS-C camera comes and goes).