Styles in LESS version matched till JQ UI buttons.
Importantly, the bootstrap.less file is now added as "reference" only. So that bootstrap css will not get included in the LESS output css.
the LESS version now matches CSS version with following differences:
1. colors do not match at times. This is due to usage of variables for colors instead of hardcoding every single color.
2. CSS corrections like using px at times.
3. Moving styles around.. this happens due to LESS compilation.

Overall the net impact will not be visible on the page.