A lot would depend on where you are hunting. Too much choke can be a bigger handicap than too little. I would probably recommend buying a modified tube for most of your use, and maybe an imp. if you do a lot of close quail hunting. My old shotgun had a modified choked barrel so that was all I had, I have been using one with tubes now for about 4 years, using both mod. and full. The quail pop in our part of the country has been down for a few years, so I don't get a chance to shoot many. I will start out the pheasant season with the mod. tube in, (younger dumber birds =closer easier shots) and then switch to full around Thanksgiving after they have been chased around and "wised up" for a month. I also mostly hunt 1/4 section CRP fields or fencelines or draws where birds will often get up a ways out there. I mostly use #5 (2 3/4") for pheasant, have been using Activ for the last couple years, but also like the Federal High Power. If I am hunting in an area that I know both pheasants and quail inhabit, I will back down to a lighter "field load" #6. Back when our quail pop was higher and a guy could expect to get into them regularly I always carried a dozen light 7 1/2s.
The full does its job on turkeys also (3 seasons, 3 shots, 3 toms), if I had the xf tube I would probably use it, but I ain't gonna spend the $ for one, I used to shoot them with my mod.