kdkd,
Interesting reply.
What broker to you use? What do you pay in commisions?
I think it might have a lot to do with how much you're investing. Perhaps if each trade were for 10K plus, I could see paying $20-$50 in commision, since it's a small fraction of the transaction, and like you say the fills may be a lot better. But if you're like many people here (I imagine; maybe just me!) many orders are for just a few thousand dollars and then cost of the full-cost commision more then negates the better fill price.
Personally, my experience with Freetrade is that it has a large psychological effect on my trading. Lots of times I'll buy something, just a taste, to see what's happening . . . and then sell it a few hours later if I'm wrong. Often I sell it for the same price I bought it at, meaning it's a no-cost transaction with no commisions ($3 or less). Also, I'm much more likely to sell off winning positions in small increments--something I'd never do if I were paying $20+ on each sale with another brokerage. Thus I've found I'm locking in profits more than I used to.
By the way, I've been following your picks with interest (and am in a few). You have a good eye. Keep up the good work!