I chose maybe so cause some of my horses have them and some don't. Dobe and Koda have to because their manes are so thick and long it is a pain to try to keep them separated while bridling. Most my other horses don't get ridden enough to really worry about it. On a horse that I ride all the time, I prefer to have a bridle path just about 2 inches long or so. Just big enough to allow for the halter or bridle but not so big that it is really noticeable. It also looks neater than having the mane just split with some under the bridle and some not.
I have a National Show Horse (arab/saddlebred) and I cut the forelock off and then the length of his ear and an inch back from there. It's what we do for saddle seat, it's not required at lower level shows, but everyone does it. It looks much nicer on him anyways because he has a pretty wimpy forelock.
My gelding has a bridle path the length of his ear laid back on his neck, per 4-H showing guidelines. Now that we're not 4-H exhibitors anymore, I might let it grow in and clip a 1-2 inch space instead, more the hunter/dressage style. He has a lot of "pony poof", and it's hard enough getting everything to lay nicely under tack with the bridle path.