I have a small deep fryer & absolutely love it. I’ve used coconut oil & bacon grease so far. I prefer bacon grease for the flavor & the fact that it’s readily available with the amount of bacon I cook.
The oil tends to be ready to go in under five minutes.
As to changing the oil: it’s not at all difficult. I turn it on for a minute or so, enough to bring the oil to liquid then pour it into the container I will use for disposal. All that remains then is to wipe out the vat with a damp paper towel. How long the oil lasts depends upon use, but it’s obvious when it needs to be changed. The oil will smoke & darken & the food will take on a flavor.
All in all the fryer is my favorite kitchen toy.