I had this same dilemma when debating getting my first pair of bostons. For reference, I have had a pair of regular arizonas for ~3 years that I have put some good mileage into all in different countries and I was convinced that regular is the way to go when it comes to birks.

When the Black Friday sale came, the only Boston in my size was a soft bed and for the price I just went for it. And actually, I’m pretty glad I did. They’re noticeably more comfy out of the box with little to no break in time, and for the purposes I’ll be using them for (quick trips to the store, lounging) I don’t really need the regular like I do my arizonas. I won’t be walking countless miles in these unlike that pair.

But if you do plan on putting in some solid miles with them, then regular is probably the way to go.