Zipper Door vs Tie Door: A zippered door keeps warm air in and cold air out better than tie doors in canvas tents. If you use a tent in cold weather I would recommend a zippered door.
Metal Zipper vs Neoprene Zipper: Most tent makers use YKK #10 neoprene zippers. A metal zipper freezes more easily than neoprene. Also metal zippers in canvas tents that are bent become unserviceable. However, some tent makers try to use metal zippers as a selling point but you have to decide which is best for you.
Stove Inside of Tent: Never place a stove on a canvas or synthetic floor for safety. Most factory floors have a cut out or zippered area for the stove. I prefer a continuous floor with no cut out or zipper area as I don't like water or bugs coming in the open area for a stove. I use a fire proof 3' x 4" fireproof mat that I place under the stove.
Actual Size of Tent: Most canvas tents made by tentmakers are not made to the exact size ordered. For example a 12'x14' might actually be 11' 6 "x 14' 6" because rolls of canvas can differ by three or four inches. But most commonly, tent makers make a smaller than listed size for canvas tents to reduce canvas cost. This reduced tent size is often called the cut size. When deciding/comparing which tent to purchase you shoud ask if the tent size listed is a cut size or actual size.
Side Wall Height: Most tent manufacturers that have a "cut size" also have shorter walls. For example, a cut size tent listibg 5' sidewalls normally have around 4' 7" side walls. Again, when deciding/comparing which canvas tents to purchase you shoud ask if the stated 5' wall height is actually 5" or a cut size of 4' 7".
Tent Life Expectancy: A good quality canvas tents should last the typical person 20-30 years. Leaving it set up for long periods of time (months) in the sun, without a fly, and storing the tent wet are the two main factors that affect canvas tents life expectancy.
SNOWLOADS: Some individuals want to leave their Montana Tents up in the winter. There is no internal frame that can withstand heavy snow loads. I know outfitters that have had to leave tents in the back country over the winter because they had to leave quickly with their clients due to heavy snowstorms to make it back to their road base camps before the horse trails became impassable. Their tents were torn and frames destroyed when the outfitters tried to retrieve their gear in the spring.