40 up and 40 down extra channels is all good with me . Although I've never really needed much more then 15 up or down extras concerning a cb radio to begin with. These 148/Grant chassies are very stable bodied radios. Some of the best receiving chassies of all time.
Solid SSB performance , drift free. I think the poorman's channel mod is a good way to go on these. Your just getting what a fine radio already has to offer. You can always add the third switch for plus channels or even a 10khz jump.
Expo kits are getting harder and harder to come by. There's certainly nothing wrong with working off the chip , Might ? just be more stable then the Expo kits ? It's just a very easy mod for somebody looking for a handful of extra's that wouldn't cost them anything if they knew how to use a few of the switches already on the radio.