This is a good question, when I first shop for scooter in the states, my first thought was YAHAMA TMAX, unfortunately they don't have it anymore and the Suzuki Burgman is just too expensive (and not so sporty) for me so I decided to move on to the other Japanese and two Taiwanese bikes.
After a quick research online, I narrowed down my pocket list to the following:
SYM Citycom 300i (263 c.c.)
Pros:cheapest among 3, 16" wheel, 2yr warranty
Cons: least powerful, no ABS
Kymco Downtown 300i (299 c.c.)
Pros: Powerful engine, large luggage space, 2yr warranty
Cons: no ABS, kymco should put European seat on this bike
Honda Forza w/ ABS (27x c.c.)
Pros: ABS!, Honda quality and reliability
Cons: not so good power/weight ratio, so so promotion and discount
In terms of build quality, I think three bikes are very close to each other.
I am from Taiwan, so I know SYM and Kymco made very reliable scooters for decades.
(I owned both brand when I was there, scooters in Taiwan were built with a easy-to-service mindset)
Honda Forza, if I remember correctly, was made in Thailand(?), which is one of the Honda's largest scooter manufacturing base and their quality is among one of the top manufacturers.
Therefore, in build quality and reliability wise, I think those three bikes are too close for me to tell the difference, so I use the cost/performance scale to evaluate them.
Citycom was eliminated first because the top speed is only rated 79 mph and slightly under-powered for my 60+ miles daily interstate commuting.
DT300i got most power among three, better discount and promotion, but I was kind of mad why only US model doesn't has ABS as standard (see Taiwanese and European version)
Forza got the ABS I want, but less power and so-so discount (I used Costco purchase program to save me some time with those dealers so I don't have to play games with them) made me decided to support the brand from my home country.
I strongly agree that you will be satisfied with either one since they are both decent bikes.
Those information above were just my personal thoughts, and as always, I could be wrong.
I will probably made a different decision if we have new Silverwing or YAMAHA TMAX in US market.