I've owned two of them, a G and a D. Flew one around in Central America and flew it back across the Gulf to Key West. They fly slow, have excellent visibility, land on a dime, do crappy acro and have limited crosswind capability. An absolute hoot to bring to air shows, especially if there is other dogs there as well. Dog owners tend to be party animals.
Parts are getting expensive. The engine has a bunch of components that are unique to that engine that are becoming scarce. The carburetor costs a minor fortune to overhaul, its pressure, not draft. Flap motors, electric fuel pumps, flap position indicators, generators and starters are also pricey overhauls.
Mods, get a cruise prop, better yet have both. You can re-pitch a climb (normal) prop to cruise. Only do it if you live near sea level. You can put it on floats. There are several different engine packages, the latest is a 540. Putting a bigger engine only gets it slightly faster, but you get a controllable pitch propeller. The -15 engine with the original controllable pitch propeller has become a real museum piece, with prop parts very scarce and apparently made from platinum. There are some weight mods along the way, but depend on your wing serial numbers. You can have a A model with D wings for example. When the Army or CAP did depot level work, they put on what they had in the supply system. So you may have different capacity fuel tanks from what the book says and you may be able to do paperwork to up your gross weight based on wing installation. There is light and heavy gear, no real difference there, just one is bouncier than the other. There is not much room to put stuff inside, very Cub like in loading.
For more fun go to the International Bird Dog Association' website. Get Menard Thompson's book, "The Lovable One Niner." If you get one, you best like traveling slowly veeerryy, slooowwly.
Mine:

Mine was painted and equipped to match my Buddy, Bob Moriarity's in Nam, based at Marble Mountain. Bob's late claim to fame, is having flown his Bonanza under the Eiffel Tower in 1987.

Getting ready to ferry back from Tegucigalpa, Honduras. Had to put the crappy white stripe on it to get it home. Something about it being all black bugged people at borders. I don't know why, it was owned by the "US Council for World Freedom!"
