I am pretty sure Foster & Son have merely changed the name in a "rebranding" effort. It is probably the same as Brooks Brothers calling their version of EG's Dover the "Algonquin".
The key feature of "Regent" is that it's made on the 888 last.
stgrim- Pick up the austerity brogues, if you think you will wear them every so often. Edward Green's austerity brogue (Beaulieu) is flattering and understated; it's the most elegant version of an austerity brogue I have seen. I would suggest wearing them as you would a black plain or cap-toe. The absence of ornamental brogueing makes them quite versatile for a black shoe.
I pretty much agree with all of that. There are one or two others that I like as well, but none I like better.
If another retailer carries a makeup one wants, then by all means one should order that makeup. I recognize the allure of special in stock makeups. However, there is something fun, and possibly even more special, about placing a unique MTO, particularly if you have fit issues, or are a former bespoke customer.
I have multiple MTOs (including Top Drawers), stock models, and store special makeups. Yet, I want to point out that in my experience, retailers will regularly waive the MTO fee or include shoe trees and/or other sweeteners to offset the MTO fee partially or wholly.
As for the wait, I have no idea what the current turnaround time is for EG MTOs and Top Drawers. I think the delivery time does fluctuate greatly. But patience is supposed to be a virtue. Cheers.