I added a heat strip to my 2019 Coleman roof AC and in my opinion it was totally worth it. Was a very simple plug and play install, the wiring was all there already from the factory. If you have a newer rig you don't need to mess with wiring or breakers or any of that, it is a simple plug-and-play to existing wiring/plugs with stupid-simple instructions and will work with your existing thermostat. It does not blow out "hot" air to the touch, but if it runs for a short while your rig will be warmer. If we have hookups, we use it as our only source of heat down to roughly 40f OSA and it easily maintains that temp.
In my opinion it is superior to portable electric heaters (which we carry in case of emergencies) because it is the same heat power yet it works with the existing hard-mount thermostats. Also, we often ran our roof air fan at night for background noise anyway, so adding heat was a no brainer. Just my experience. It works great for us.