cyclezen

The Dec Triban RC120 seems like quite a nice bike for the price, and when it was on sale for $398 - a great deal.
My only reservation would be getting a pre-assembled one from Walmart. I'd sooner take a boxed one and either assemble (if you know what you're doin) or give to a bike shop for assembly.
Getting something improperly assembled might prove risky, both for safety and not breaking something which would add to the cost...
And whatever brakes offered is fine. Mech disc or rim, they can be made to work properly.
With proper attention to maintenance, it should be a good entry in road bikes and road riding. Well above your average Big Box gas pipe.
Ride On
Yuri
EDIT: couple other things: wheels size & tires designated '28' are in fact the same as 700c (the dominant road bike std size, with 650b being smaller). 28 is old school sizing, and still used by some companies - like Schwalbe... a bit confusing for sure...
biggest caveat, especially when reading reviews about eventual 'shifting' issues - cables for the shifting and braking ALWAYS stretch, after some use. Brake cable means slight adjustment via adjusters on the brake caliper (also sometimes available on the brake levers) - something most users can do easily.
Shifter cables WILL stretch, and over time, cause mis-shifting and further on, jumping gears. This is usually NOT an indication of poor or worn tech, just stretched cables. Most novice or beginner users are not aware of this and reviews blame it on equipment wear or poor performance. Cable adjsutment usually takes care of this. A good thing for every rider to learn, as regular maintenance.
Cables need to be adjusted - for those who can't or won;t do that - shops can do it in 5 - 10 min...
Cheap, quick stretching cables are common on the lower tier of bikes - replacing them with good cables is a cheap fix, when the time comes...