San Marco Rolls Titanio is all I use, on road or MTB. It's the one single component where weight weenie is a big No No and what other people consider it to be hefty, ancient or it doesn't look right I don't care one bit. When set-up properly (right height, slightly dipped so the nose is a touch lower than the slightly raised back), broken in after only a few rides and wearing decent padded shorts there's comfort from the first minute all the way to +8 hrs later. I tried a Flite Ti which is very popular but for me I thought is was the equivalent of sitting spread eagled across a breeze block; a 3 hr ride took me off the bike altogether for 5 days. As said, it's personal but when you do find the one that works for you, stock up!