The top of the range Digitrax controller [ DT402R] has every thing you could want for except a on off switch.
This controller has a 9 volt battery that goes flat after about 3 hours if the battery is left in the unit. To this end a on/off switch can be fitted but will more than likely do away with the warranty.
The 9 volt batteries are not cheap locally. I purchased from Hong Kong via ebay and the cost for 4 rechargeable batteries, a charger and delivery to Australia for $16.00. Good buying.
I have numbered the batteries so as to keep track of the charged and flat ones.
Shame on Digitrax not installing a ON/OFF switch. Most of the folks I know have sent emails to Digitrax and like me have not had a reply.
That aside I still like Digitrax. I suppose its what you feel comfortable with.
I agree once again Don and I did install a small slide switch in mine but even more anoying to me is the non-detachable short cable coming out the top that catches on all of the scenery and bill boxes around the layout.
I got rid of the Radio and am now teathered.
I found the MRC radio to be fall better than Digitrax.
My first system was a Digitrax and I have changed over to NCE. Their radio throttle does have an on/off function, and will power down after several minutes if you forget to shut it off. It has a short antenna on top, or there is a modification to remove it and replace it with an internal antenna. Having used both versions I fnd that the short antenna does not bother me.