I personaly like the wide band as its most popular at the moment and compatible with many at this point in time.
However be aware that the FCC has proposed and set a dead line date to eliminate the wide band 25 khz radios and pushing all into the 12.5 narrow band to make twice the freq ch available.
This dead line was 10 years last time i heard say 2 years ago or so.
So figure posibly 8 years or less your wide band will be no longer allowed .
Granted many will say the FCC has post poned the dead line and many other claims ect.
My info as a FCC coordinator was that this was on a per situation basis and may or may not apply.
So im not 100 percent sure id care to say the wide band will remain or not.
Best bet would be to go the 12.5 narrow band just in case.
Or consider purchasing for example a Motorola 1225 mobile or portable as they will program to eigther narrow band 12.5 or 25 khz wide band by simply selecting the setting you need = its built into the radio both ways.
Also be aware that many companies built the crystal to swap a 25 wide to narrow operation for many radio types on a per order basis.
CES is one company that does this.
Motorola does have narrow band conversion kits for many of its radios such as the Maxtrac and GP300 and P110 that are available as well.
If you search my posts you will run across a posting i had on the 25 to 12.5 conversion process.
My stand is that i feel 12.5 WILL in fact be placed into effect in time and as such i have already put into stock conversion kits for the Motorola products i feel i will have to deal with when the time comes.
Be assured ive been wrong before on things as far as the FCC rulings and could be wrong on the 12.5 issue but i wouldnt bet against it.
Just as a closing coment = The FCC has already issued 12.5 licenses which require 12.5 narrow band radios .
And aparenty you yourself just ran into one of the 12.5 radios which is intended to be used with just those licenses.
Also if you wanted you could order the 12.5 filter crystal for the SP50 and the other components that made the SP50 a narrow band rather than wide band for future conversion if you were so inclined.
If you want to pursue this option id call Motorola at 1-800-422-4210 and ask for parts ID and give the individual your SP50 model number and ask them if they have a complete conversion kit for your radio that goes from a 25 khz wide band to 12.5 narrow band.
You probably wont be able to buy it without a MOL account but if you get the part number many here including myself can order it for you.
Oh yeah welcome to the real confusing world of radio / I think