Good to hear
Good to hear that the 175 is not performance limited out of SOU because as our most successful base it would have been foolish to buy an aircraft that you couldn't use from there.
In terms of why the 175 is better it's a far superior aircraft to travel on - quieter, smoother, less vibration, more room, better seats, faster. Frankly it staggers me that so many people are prepared to entertain the Dash - especially on the longer routes out of SOU (say anything over 1.5 hrs - and that's a lot of routes). Every time I fly as a pax I'm astounded how noisy it is in the cabin with all that resonance from the overhead bins etc.
And that's before you touch on the thorny subject of reliability...
DP