I don't own a 125 scooter yet, but I've been riding 50cc for 6 years so I know the limitations of one.
Granted they are a lot of fun, but sometimes you need more mph!
You will be able to cruise comfortably on 45-50mph roads. You will be able to jump onto 55mph roads for short lengths to get from point A to point B. Since most cagers are doing 70mph on these road, it's not some place you'll want to spend a lot of time. For that type of riding I agree with a 150-250cc scoot.
As for the Agility 125 which I've strongly considered myself, you can add a top case, windshield, saddle bags, rear basket, etc. Whatever you need to use for your style of riding.
Go for it! Lower cost used ones can be found easily.