Life Application Commentary for the NT (premium e-Sword module) was made with T4. If it's good enough for official e-Sword, it ought to be good enough for you. (Sidenote: I have this module, and I recommend it).
Rick Meyers has told me he likes and very much appreciates the work Brent has done.
T4 would cost tens of thousands of dollars to develop from scratch, paying hourly programming rates (like a company would).
Everything I make goes through T4. T4 goes beyond module making
It allows for the wide scale manipulation of text required to make good modules.
It has the best tooltipping and error checking algorithm I've ever seen (yall do know, there's more than one Bible software company that assumes every number:number is a valid reference, with no checking at all).
It allows you to automate the mass creation of database records with predefined symbols.
Virtually everyone who makes modules on a regular basis, uses T4. If I left you off the list, it's probably because I'm not sure if you use T4:
Josh H. uses T4
Patchworkkid uses T4
David Psalms uses T4
Larry G uses T4
Tom Rightmer uses T4
Doctor Dave uses T4
James Rice uses T4
Journey uses T4
Bill Huff uses T4
Pfpeller uses T4
Brad Cobb uses T4
Scribe uses T4
David (of Psalm4.org) uses T4
About a dozen "non-public" module makers use T4--they've contacted me asking questions. They make modules for their church, their Bible study, their Sunday school class, etc. Undoubtedly, there's more than a dozen. There's just a dozen that I know of.
The biggest fault of T4 currently is I've let the documentation get way out of date. There's a number of new, undocumented features and the tooltipping algorithm has changed (for the better) since I wrote the documentation.