I gather the latest Buddy-170 and Sym HD200(evo) have definite similarities in 170cc engine size, fuel injection, and lack of kickstart [Shame!! Each should have a kickstart plus a small lithium battery "back-up" for the ecu & efi. Admittedly that would add about $100 to the base cost ~ but that extra cost would be forgiven, even blessed, on the first occasion when you discover that the main battery is flat.].
Apart from that, they are very different creatures : very much apples & oranges.
The Sym HD200 is about 50 lb heavier, has 16" (versus 10") wheels, and about one-third more power [very noticeable out on country roads, and even more so when against a bit of headwind].
As a minor point, the Sym fuel tank is about 1 L bigger (7.5 versus 6.5 L) ~ which is not much extra . . . but would give roughly 20% longer "useful tank range" for similar riding conditions.
For city riders on slow or on very twisty roads, the Buddy-170 would be fine . . . and looks like a classic small scooter (very neat).
For "Advrider" touring and general country roads [even dirt], the Sym HD200 romps it in. The "high" speed handling and 16" wheels are the clincher, and the other advantages are just icing on the cake.