A blade brake is great when you bag, as you would otherwise have to keep stopping and restarting the engine. It's somewhat useful, but maybe less of a priority when you side-discharge or mulch in that it only comes into play when you stop to move a rock or a branch or a toy.

If you bag, I'd say it's worth it.

As far as the variable-speed goes, you might want to look / try the differences yourself.

::::::: No disrespect to Axiom, but my favorite woofer is my yellow lab :::::::