Nice one Angus :thumbsup:
After you get used to using the urethane grout, in my opinion, it's actually easier to install. Urethane grout causes problems for people who treat it like normal grout. Fact is that it has so many advantages over epoxy and standard cementuous grout, it's silly to fight it as at least a viable alternative, if not the truly superior product.
Vs Cementuos Grout
More flexible, less likely to crack.
Premixed, so color always matches.
Inherently waterproof, no sealing required, ever.
Clean as you go (easier in my opinion)
Vs Epoxy Grout
More flexible, less likely to crack.
Water cleanup
Premixed, so color always matches.
There are some applications where epoxy is superior, like a commercial kitchen floor, or a tiled hot tub at a spa or something like that. There aren't any applications where cementuous grout is superior to urethane, except that it is cheap.
Edit: Here's a video of a guy showing how it's done. Have a helper clean as you go, and you'll be every bit as fast, if not faster than with cementuous grout.