I believe that's about as best anyone ever really feels about Big Dots. I have a hard time believing that anyone claiming to "love them" really shoots them very much.
HD's or I-Dot's with the rear U notch (for me at least) are everything Big Dots wanted to be.
I-Dot vs. Big Dot size comparison:
Sight Picture: (front stands out better in person, camera kept auto-focusing on the rear)
Sounds about right to me. One of my G19s have Big Dots and I really want to love them, but it always takes a while on each range trip to figure out where to hold. Once I get it figured out, I'm ok with them, but with each range trip, it starts all over. I'd probably be Ok if they were on every gun I own, but I'd never do that and so I find myself needing to figure them out on each range trip.