sv650 is a nice bike, its air filter is located under the tank and its frame goes on boths sides of the engine - like on supersport bikes

mt-07 is more utilitarian and uses an old 70's UJM bikes compound - airbox is under the seat, frame goes on top of the engine and under the tank

mt is better for stunt or track build, easier to work on due to the reasons above.
mt is more common, and its engine can be found in many other yamaha bikes, meaning more parts and custom options, it is also the most reliable engine in existence. some people put a turbo on it

sv has a v-twin like on some of the most legendary bikes out there, like Ducati or whatever. mt has a p-twin which is again easier to work on and lighter.

the tank on the sv is made of metal, so you can scarp it or dent it, yamaha is made of plastic meaning you can easily fix or change parts

so if you want to own something nice and special just because - sv
if want to ride - mt