The Sport Ultra does not use Kangaroo leather but normal cow leather; they're not as comfortable as the Tour Ultras with the kangaroo.
The 3G, both Tour and Sport Ultra do not come with the adjustable heel and sole on the non-sliding shoe.
The 3G have a border of some fixed leather on the adjustable sole area. Personally I found that interfered with the slide ability of whichever sole I wanted to use. So you alwyas had 2 different friction levels, even if the border was narrow.
The 3G do not come in a wide. The Tour Ultras with their kanagroo leather was very stretchable and felt very soft but they are still not a WIDE, if you need a wide.
Personally I went to the Dexter SST-8s last year because of their superior adjustability. I had to use the 3G sole with the cleats or inserts to get the slide I needed; then they began to come apart. Dexters, for me, have never been a long lasting bowling shoe, but I took a chance anyway since they gave me the ability to slide with much less hassle than the 3G. I last tried a pair of Dexter SST-%s when they first came out and they started to fall apart after 2 or 3 months; so I never regarded Dexter as a "quality shoe". I regarded Linds, when they were made in the USA as the very best bowling shoe by a HUGE margin. A single pair used to last 15 years or more; until you got tired of looking at them. Since then Linds were made in Mexico, then in China. I gave up on them a long time ago.
Right now, the Dexters are last and show no signs of the stitching coming apart.; the soles are lasting a long time. They are far too stiff to be called comfortable; I just wear thick socks with them. They do run a little big. I normally take an 11 1/2 but if I wear summer weight socks, the shoes are pretty loose.
I think I paid $135 or so for them; if I get 2 full years from them I would be satisfied. I should get 10 years for that price but since quality is not "job #1", I don't really expect to get that.