The NOS heater is a good choice as it is a 300 watt heater and will heat a bottle in 80% of the time a 240 watt will (NX). In my web in the links is the manufacturer of the the electronic thermastats that NOS uses. I change from the *85's to the *95's and now bottle heats to 1150psi on a full bottle. This is great for dry hits, but on wet raising pressure above manufacturers rec press will throw your a/f out of wack. This doesn't happen on a dry hit, it's like putting in bigger jets.

Also, with elect transducer when bottle no longer heats higher than 900psi it means there is about 3-pounds n2o left. Try that with a mech transducer that ugly hangs off your bottle.
Robert
Edit: I run a crappy NX heater with the NOS *95 thermastats.