Here's my lean on things; the only thing I've ever ridden were either ultegra or 105 in road bikes. 105 has been very dependable for me, rock solid performance. I've just grown to be quite confident in 105. Ultegra is nice too; but the lastest 6700 rendition seems a lot more 'tin-ee' sounding and just does not give me that 'solid' feel to it as I shift. I think hollow technology or some such meant to save a few grams is the reason for that 'tin-ee' sound to it. I don't like it as much, even though, it does what it's meant to do, which is shift gears in a timely fashion. Past ultegra was better IMHO. My old 9 speed ultegra (6300 was it? too lazy to look it up just now) aluminum Trek was also rock solid in performance without the 'tin-ee' sound.

I've changed my thinking over the years, and used to think the 105 bikes were lesser quality [they do price in a lesser range]. Now, I LOOK for the 105 models and ask for it [I don't buy bikes every day of course].

I've always wanted to try dura ace just to compare, but could never afford it [has anyone noted the gigantic jump in price to dura ace? Titanium no doubt?]. I'd also like to try SRAM, but who gets to own so many bikes that they peruse all of what's available [maybe the pros, who knows?]. As far as raw performance and disregarding weight [my 105 bikes come in from 18 to 20 lbs; my ultegra bikes are usually 16-18 lbs], it's all 105 for me. I'm not a racer, so weight is not critical [especially when I could save bunches by just going on diet, LOL].

[though I see apparently they are trying to hawk the tiagra components again as somehow being upgraded from a few years ago. Last I purchased and checked things out more up close and personal was 2010...so maybe things have changed, I dunno. 105 for me though, tried and true].