Generally speaking you have two types of bases- extruded and sintered.
Extruded bases are much cheaper and usually found on lower end skis. They are pretty durable but do not absorb wax well. In fact, hot waxing an extruded base does not really do much since the wax stays on the surface of the base and does not penetrate the base. It will only last for a a few runs, so you are better off not wasting all the time and money on hot waxing and just getting a simple rub-on wax designed for extruded bases, like Maxi Glide.
Sintered bases will out perform extruded bases in terms of durability and speed, but only if you properly maintain them through regular waxing. Sintered bases come in grades, usually 1000 series up to 7000 series. The higher the number the faster your base will be, but again only through proper waxing. A sintered base that goes unwaxed (say 2 weeks) will look like dry skin- white and pale. Hot waxing will not bring this back to life because the material has dried out and needs to be ground off. So only after a belt and stone grind will you be able to wax that base properly again.
Sometimes companies advertise they have a "race base" when in reality it is only a basic sintered base. Sadly, not all companies list the exact series their base material is so sometimes it can be hard to find out.