Filter on the 31mm

Ok, having acquired the 31mm I've thought about getting a filter for it. only a UV, but I'm wondering, will a cheap one have much of a difference between a more expensive one? e.g. is it worth the extra to get a Hoya HD, instead of the standard Hoya UV filters? (3 times difference in price?!)

I've never really used filters, so apologies for another silly question, though it's probably not just for the 31mm, it'll obviously apply to all lenses.

Since some topics here there are some that stop using filters for protection so maybe there is someone on the forum that has one for you?

Thanks Bertie, very detailed and scientific test indeed, though I really haven't got the effort at the moment to read into it, the summary did well for me though!

Stefan, Thanks for the heads up again, a quick search does indeed bring up two camps.

I'm a bit of both, as with a big hood I really wouldn't worry about it but with the 31mm I think I might cover it up this time with a filter though as I'll most likely encounter quite a fair amount of dust and possibly water.

Thank you!