Perfect example of how this "feeling" is completely subjective. Mechanic "feels" the LA-7 is the superior stall fighter.
Mechanic feels it because the difference is there. Performance charts are only useful for few basic metrics. You should have know that...
I bet that if we could turn the cockpit off and all other distinguishing features neither one of you could consistently tell them apart from low speed performance alone.
In AH, LA7 feels differently at slow speeds. It's not as stable at these speeds and high angle of attack as LA5, hence you can throw it around better than LA5. Whilst difference is not huge, it is very much detectable if you fly both a lot.
In short: less stability = more maneuverability, and that, in essence, is difference between LA5 and LA7.