There is a huge difference. Go with the Digitrax zephyer, MRC Prodigy advanced/express, ore i think the new NCE power cab.
Bachmann's system is designed as an accessory to their decoder equipped standard line as a cheap dcc system that parents might get their kids for their trains. Its an extremely limited system. there are no upgrades. the more expensive systems are definitely the way to go. they are a high initial investment, but are definitely worth it.