Most ships still have equivalent sensor strengths and profiles. Unless one of the ships involved has asymmetric sensor stats, sensor encounters will remain symmetric.
As long as the UI effectively communicates how the system works, I don't really have any problems with it. People are making noise about large schools of frigates, but generally, you're only going to care about the big ships anyway.
And with the exception of modifiers, sensor strength was always tied to hull size. Frigates were 1, destroyers 2, cruisers 3, and capitals 4. Then the whole fleet was all summed up and passed through a funny equation. This ditches the equation and makes it "base plus the five most important ships".
EDIT: Fixes numbers.
EDIT 2: Looks like I'm repeating stuff Alex said a few posts up. Whoops.