I look at the CAB-1L as basically a CAB 1 with a Legacy transmitter in side, updated firmware, and a modified push button electronics.
You quill the whistle by pushing the button harder.
It has room for 2 digit train and track numbers.
There is no external antenna, but the rest of it looks like the old CAB-1. The model I saw was built from CAB-1 parts, and there' no reason at all to redesign them.
The transmitter parts that were discontinued, which caused the discontinuation of the CAB-1, were from the CB radio design days. That technology is no longer supported by parts suppliers.
The new Legacy transmitter uses technology similar to the cell phone world, so parts will be around a while.But that means CAB-1L only talks to the Legacy base. So it's not a direct replacement for a CAB-1, but more of an entry level Legacy controller that TMCC'ers would automatically be comfortable with.
Lionel was very clever in bringing back something the customer wanted, and doing it economically - and with proven technology. And it will help migrate users to Legacy.
Elegantly simple.
To my way of thinking, that's some fine engineering!