Hi gurocat, welcome to the board. I agree that it was sad when this mod didn't work with 3.19. I even waited a while to update so I could continue playing this mod. I still remember the chuckle I got out of seeing the massive city radius for the first time while setting my workers in the city view screen. It was freaking hilarious.
After this mod no longer worked with the update I pretty much just played vanilla BTS, with some text tweaks. Then I discovered the wonder that is the Multiple Production Mod.
http://forums.civfanatics.com/showthread.php?t=326545
I was excited for a time thinking that Mylon's expanded city radius would be combined with the multiple production mod. A board member by the name of Arri stated that he might try to combine these two ideas and make it compatible with 3.19, as discussed in the following thread.
http://forums.civfanatics.com/showthread.php?t=241976&page=11
It is true that there are several mods that have combined both of these ideas, the only problem is that they have so many mod components in the game that stability can be an issue, which was never the case with Mylon's mod. I am however, thinking about trying Rise of Mankind: A New Dawn, the mod made by Afforess. Like Mylon , he seems to have made a quality mod. I believe that I have read on these boards that some of the issues with the larger mods can be sorted out by disabling UAC ( User Account Control ) in Vista, so I am hopeful of it being playable on my system.
I do admit that I feel a little bit bad for Jon Shafer, he cared a great deal about the civilization franchise and must have felt honored to be put in charge as the lead designer of Civ 5. That being said, something has gone horribly wrong with the latest installment of Civilization and I find it hard to believe that it will ever be fixed.
Luckily for me, this game was released Steam only, so it will never get the opportunity to disappoint me.