I have and have had a number of lever guns over the years that had that type of sight on them, and they do work well. I didnt realize they updated them to work with the scope mount holes on top, which is cool.
My only complaint with them is, crap tends to hang up on them, and the "smaller" XS type peeps are a lot less of a snag issue.
“The enemy is anybody who's going to get you killed, no matter which side he is on.” ― Joseph Heller, Catch-22
Beware of associating with "Cheap" Squirrels. They tend to be very narrow minded, hypocritical, and will gag you if you question or disagree.