I know the Balance well... It was one of my favorites before I crossed over to "The Dark Side."
The idea that they're touting - simplicity and streamlinedness - are ABSOLUTELY two huge features to look for in a BC... And the Balance definitely fits that bill as compared to a lot of BC's out there.
If I remember correctly (it's been several years and many thousands of dives since I last dove one), the Balance also features a sort of "backplate" built in which helps add stability, despite the simplicity of the rig. Stability is also a great feature in a BC.
That said, the Balance is missing a crotch strap (as most BCs are) and instead rely on a cummerbund to keep it "down" when inflated at the surface. The problem with a cummerbund is that they tend to press upwards at your belly, restricting movement of your diaphragm - especially when they're inflated.
The Balance also is missing the ability to change bladders (wings) - again, as many BCs do - which can be necessary to dive various situations. For example, in tropical climes where wetsuits and weighting are minimal, a diver may want to wear a small, streamlined and easy-to-manage wing. For colder climes with heavier suits (or drysuits) and more weighting, a diver may need more lift and thus a bigger wing. Other times, he may choose to dive doubles, which requires a completely different wing.
The Balance (and many BCs) can not accomodate all of these situations, and is really a tropical-only BC (for single-tank rigs in warm water).
A much simpler, balanced, streamlined, rugged, durable, and flexible rig is a backplate and wing... Although if I tell you that, I may start sounding like a broken record...
Let me ask you this... What "type" of diving do you plan to do? Do you ever plan to dive anything but the tropics?
Here's another resource, which I wrote several years ago:
http://www.deepsouthdivers.org/old/homebc.html
...One more thing stands out in my mind about ALL SeaQuest BCs... They only have ONE tank strap, and it's a crappy design. Check out ScubaPro's awesome stainless steel fully-opening tank straps, and you'll turn green with envy.
Interestingly, if you choose to dive a backplate and wing, you can pick whatever tank straps you want (they're standard 2" straps throughout the industry, and ANY strap will fit most any backplate and wing). For this reason, I wear TWO ScubaPro tank straps on my BP/wing and would highly recommend it.