Higgins and O'Sullivan i think you mean, Not heard of Davis using them.
Elks and the ever so slightly harder blue diamond have been the only tips in the uk for donkeys years, the intenet has since opened up the market.
I've always bought elks though the number of duff uns in a box seems to be more nowadays and it's led many to try others. The talisman soft are the best i think they hold the chalk well keep their shape far better, last longer and are only marginally harder as long as you buy the bigger ones.The smaller ones just aint the same quality i've heard. At £5 a tip they are 10 times the cost so it's false economy really duff elks aint that common in a box.