Exercise equipment is being produced for a wide array of users, so it's understandable that you'll come across both high class and low class home gyms. Band Flex belongs to entry level home gyms with a price as low as $300.
With Stamina Band Flex, you will be able to do 60 exercises that will affect your entire body, but with only 130lbs of resistance, which is not a lot when compared to some home gyms produced by other manufacturers. You can have 260lbs of resistance when using leg curls and arm curls, though. While that will be enough for most people, serious users won't be satisfied. It's also worth mentioning that a maximum user weight is 260 lbs, which says something about the quality of construction. Frame warranty is only 5 years, so look elsewhere if you're after a long term exercising partner.
In conclusion, Band Flex is a solid home gym for beginners and non demanding users. You can use it to stay in shape and give your body a definition, but you'll have to find a better model if you're looking for anything more than that.