it depends. all the basic bottle warmers are gonna heat the same. the expensive $200, NX bottle warmer will be different then the NOS one you have. but that is auto-temp regulated. this means that it will turn itself on and off depending on what the bottle pressure is. if you want to go that route, it will help.
i always just used a normal bottle heater and had a pressure guage. it works. it may not heat up quickly, but you never wanna heat a gas up too quickly anyway. dont know if you do this or not, but one quicker way to heat up the bottle is to keep it closed and have the warmer turned on. that will heat it up a tad quicker, but you won't be able to know the pressure... just dont leave it on too long and youre fine.
bottom line. stick with the NOS one to save some money