I have been looking at these too. Only 2 that have reverse are Gatortail and Prodrive. Gatortail reverse works like an outboard reverse where the prop spins in an opposite direction. Prodrive reverse is different in that the skeg actually rotates 180 degrees so the prop is always spinning the same way. With the Prodrive they have manual reverse which is standard and hydro reverse which is a 1500 option. These motors are expensive the 35 hp tiller versions for both brands run about 7K with reverse. Mud Buddy is cheaper but its because they don't have reverse. Gatortail is belt driven and Prodrive is shaft driven. GT will be a little faster since it is belt driven. You can mod these motors because they are just large lawn mower engines. When you mod them you lose reliabilty. People have trouble with oil leaks and stuff from blowing head gaskets and the case gasket will start to leak because the compression is higher when you mod it. Buddy had a 35 hp modded that was estimated at over 70 hp and he blew a head gasket quite often. He told me not to get a modded motor and just stick with stock because you won't have as much trouble with it. The boat does matter a lot. These motors are designed to run on boats that are completly flat on the bottom. They run like crap on a mod V boat. They will run ok on a flat jon but they run best on a mud boat. Flat jons usually have ribs in the bottom and the mud boats are completly smooth on the bottom and they are made much better and are at least .125" thick in the hull. Also a longer boat runs better with these motors. A 1848 should run faster than a 1648 with the same motor. Not sure why that is but ask any of the people who make these boat/motors and they will tell you the same. Both prodrive and GT make boats and motors. A new rig with a 35 hp will be at least 15K so that is a con. From what I've seen a 35 mud motor rig runs about like a 25 outboard as far as speed. I mean there going to run in mid 20's with a load and maybe close to 30 mph unloaded. But the difference is they will run that speed in shallow water where an outboard will be slow.