Hi m.
As a way to enter DCC, the Bachmann system has simplicity as its advantage. However, it is very limiting in other ways, especially when it comes to expansion options. The primary issues are a lack (at present) of a computer interface, the limitation of only being able to use 10 different addresses, and the lack of programming ability beyond address. You can't control points or signals from it either.
For a similar price a Roco start set gives you 99 loco adresses, availability of a computer interface, programming of CVs, a decoder fitted locomotive and some wagons, and a circle of track. OK, the locomotive is german outline, but you could rob the decoder out of it and sell it on ebay! Other accessories available include a very handy points control module.
A very nice standalone controller is the Digitrax Zephyr, which also represents very good value for money. It is capable of 9,999 locomotive addresses, point signal control and lots more... all in all nearly as much as some systems twice the price.
I would recommend signing up to the DCC UK yahoo group (
http://groups.yahoo.com/group/DCCUK) for a comparison chart of DCC systems, and a general wealth of knowledge.
HTH
Richie