I have two, one from Panther, and one from Tentsmiths. I went with the Tentsmith's version for my second tent as at that time Panther had some quality issues. BUT their warranty has been always honored, so I know folks that got some tents with seam sewing problems and had them corrected without problems.
IF you are going to do a bell on any size tent, get the bigger bell, or the biggest bell. It is a great place to store stuff.
IF you do more camping in colder weather or with colder mornings, get the mug flaps, as it cuts down on drafts. If you do summer camping and it gets sweltering hot, omit the mud flaps. You want that air circulation.
IF you do living history events as part of a military unit, and your tent will be in a "company street", then consider getting the bell with a rear opening that you can modify and secure with large hooks and eyes. After hours it makes a huge difference being able to open the front and back for a few minutes and letting the hot air out. If you go to events where the public is often behind the tent..., omit the opening and keep it traditional design, for it lowers the thievery by tourists.
For winter camping the bell is the best place to put the heat resistant opening for your tent stove, stove pipe. The slope of the sides of a tent cause such openings to leak when the stove pipe is present and it rains. Leaking in the bell area is much preferred to leaking anywhere on the main walls near where somebody sleeps.
I hope this helps.
LD