I have two problems with the reserved slots and kicking slots concept.
1) The server shows up as 30/32, but two slots are reserved, so it's really a 30/30. That's an annoyance, especially with the new auto-search. I can live with it though.
2) The server lets you in, you're playing, but all of a sudden you get kicked because a reserved lister joined and the server needs to clear another two reserved slots. That's the stuff that causes me to blacklist the server, because I don't want to play on a server that kicks you mid-game while doing nothing wrong.
Those types of servers I can agree with are worth just black listing. You can not join it as when you try, the game does join, then gets kicked giveing you a message that MUST be clicked on before you can try to re-join.
Getting kicked is always going to suck, but at least on the server I play on it is a little nicer. It defaults to some in-built rules, with one being people staying in spawn (ie: afk) are first to go. You get a message, "20 seconds to leave spawn or be kicked", then it counts down. Only a issue with the teams are unbalanced and your who team is being spawn camped, so 1/2 the server could be kicked on short notice.