I have a 'slicked up' MTB, a Dawes Giro 500 sports tourer and a Spesh SWorks.
The Dawes is 1 mph ( on average on a 24 mile commute ) quicker than the MTB. The SWorks is 1.5 mph ( on average on a 24 mile commute ) quicker than the Dawes.
I also have a 26" upright gent's bike which is 1 mph ( on average on a 24 mile commute ) slower than the slicked-up MTB.
I also have a BSA 20 shopping bike which is 2 mph ( on average on a 24 mile commute ) slower than the slicked-up MTB.
I have not yet completed the 24 mile commute on my Moulton Mini
The Dawes is 1 mph ( on average on a 24 mile commute ) quicker than the MTB. The SWorks is 1.5 mph ( on average on a 24 mile commute ) quicker than the Dawes.
I also have a 26" upright gent's bike which is 1 mph ( on average on a 24 mile commute ) slower than the slicked-up MTB.
I also have a BSA 20 shopping bike which is 2 mph ( on average on a 24 mile commute ) slower than the slicked-up MTB.
I have not yet completed the 24 mile commute on my Moulton Mini