Wellies for me..every time
Pro's for wellies..
Cheap - caves tend to wear stuff out very very quickly, so I find a buy cheap, buy regularly attitude helps, I view kneepads/gloves/wellies and to a certain extent over suits as expendable items that will be replaced fairly regularly.
Snag free - nowt worse on a ladder than having laces/buckles/velcrostraps/eyelets etc snag on the wires. and to some extent - the same applies to your srt footloop/foot jammer.
hi sided therefore no annoying gravel getting down the sides of your ankle and rubbing.
grippy - depending on manufacturer
Easy clean after those muddy derbyshire caves/walk back through all the sheep/cow shit
retain water - this can be seen as a plus. Wetsuit socks work by retaining the water warmed up initially by your body next to the skin. Your worst enemy in a wet suit (or wetsuit socks) is 'flushing' i.e. the contstant replacement of the warm water, with fresh cold.
In a very wet cave with a fast running stream, you end up with a constant flushing effect - your feet are gonna get cold.
Many people melt little drain holes into their wellies, but I reckon that leads to cold feet. Intact wellies help keep that warm water next to your feet.
However - I must admit that a lot of crawling in toecap boots tends to put a hole in the toe anyhow and thus provides natural drainage.
I guess it depends on what type of caving you do most of.
Ankle support - if you ask an expert, good ankle support generally comes from the quality of the sole, not the material around the ankle. I have 'flippy' ankles, but cant think that I've ever, ever, flipped one whilst wearing wellies. A snug fit of a decent pair of wellies i.e. ones with a good sturdy sole such as suretreads provides all the anklesupport you need.
How many fell runners do you see wearing shoes with so called 'ankle support'.
Cons
errr.. I guess new ones fill up with water a bit, its not hard to tip your leg up and drain them though.