I haven't used a full Dura-Ace or Record groupset, I've had Tiagra, 105, Ultegra, Mirage, Veloce, Daytona and Chorus (with very nice FRM chainset and brakes) on various bikes. I found that Campag shifting felt more precise when properly set up, but was far less tolerant of less than spot set-up.
I found I preferred the thicker hoods of Shimano shifters, Campag shifters just give you less to hold onto when riding on the hoods, but very much prefer the separate thumb shift and paddle of Campag, I on more than one occasion have hit the wrong paddle using Shimano, shifting down instead of up, or vice versa, but maybe I'm just too uncoordinated. Interestingly I found Campag's Mirage shifters just as functional and precise as Chorus shifters, the Chorus was more pleasurable to use, because it felt better made, but it didn't function any better, although the Mirage shifters used to rattle most irritatingly if you were riding on a poor road surface. So I totally see the point in buying a better groupset, but in my experience you get better finish and lighter weight, but not necessarily better functioning.
Two years ago I built up my current road bike around a SRAM Force groupset and it’s been a complete revelation. Really comfortable and chunky hoods on the shifters and incredibly accurate and intuitive shifting. I was really worried that the short/long throw shifting with the single lever might prove to be inaccurate/ messy, but it’s been completely the opposite, spot on accurate and totally intuitive. As you can see I’ve become a convert, but what I’m getting at is I think it’s really all about personal preference. Before deciding on whether to go with Shimano, Campagnolo or SRAM try all three systems and see which YOU prefer, then, once you’ve decided which system you prefer, decide which groupset within the system gives your preferred compromise of cost/weight/finish. I don’t think you can easily compare say Shimano Dura-Ace and SRAM Red, I’d go for SRAM Red without batting an eyelid, but that’s because I prefer SRAM shifting, don’t care if the Dura-Ace is lighter/has stiffer cranks/better breaking because you can tune this by using other manufacturers components, e.g. I use Zero Gravity –Ve G brakes. That’s my take on this.
I haven't used a full Dura-Ace or Record groupset, I've had Tiagra, 105, Ultegra, Mirage, Veloce, Daytona and Chorus (with very nice FRM chainset and brakes) on various bikes. I found that Campag shifting felt more precise when properly set up, but was far less tolerant of less than spot set-up.
I found I preferred the thicker hoods of Shimano shifters, Campag shifters just give you less to hold onto when riding on the hoods, but very much prefer the separate thumb shift and paddle of Campag, I on more than one occasion have hit the wrong paddle using Shimano, shifting down instead of up, or vice versa, but maybe I'm just too uncoordinated. Interestingly I found Campag's Mirage shifters just as functional and precise as Chorus shifters, the Chorus was more pleasurable to use, because it felt better made, but it didn't function any better, although the Mirage shifters used to rattle most irritatingly if you were riding on a poor road surface. So I totally see the point in buying a better groupset, but in my experience you get better finish and lighter weight, but not necessarily better functioning.
Two years ago I built up my current road bike around a SRAM Force groupset and it’s been a complete revelation. Really comfortable and chunky hoods on the shifters and incredibly accurate and intuitive shifting. I was really worried that the short/long throw shifting with the single lever might prove to be inaccurate/ messy, but it’s been completely the opposite, spot on accurate and totally intuitive. As you can see I’ve become a convert, but what I’m getting at is I think it’s really all about personal preference. Before deciding on whether to go with Shimano, Campagnolo or SRAM try all three systems and see which YOU prefer, then, once you’ve decided which system you prefer, decide which groupset within the system gives your preferred compromise of cost/weight/finish. I don’t think you can easily compare say Shimano Dura-Ace and SRAM Red, I’d go for SRAM Red without batting an eyelid, but that’s because I prefer SRAM shifting, don’t care if the Dura-Ace is lighter/has stiffer cranks/better breaking because you can tune this by using other manufacturers components, e.g. I use Zero Gravity –Ve G brakes. That’s my take on this.