I prefer tournaments with a lot of bad players in them, because that allow me to win. On a more serious note I prefer fields up to around 300 players, because they allow me to reach the final table regularly, and this is, where all the money is. Large tournaments can be exiting, but they are a bit like buying a lottery ticket.
I honestly dont understand, why people care about reentry or rebuy. To me its a non-issue. If its not possible, I play another one, when I bust, since I have no other choise. But typically the next tournament is just around the corner anyway, so no big deal. If reentry or rebuy is possible, I decide from tournament to tournament, if I am going to fire another bullet or not.
I ideally prefer for late registration to end as quickly as possible, but a long late registration period is not a deal breaker for me. It does however affect play, because it pushes the average stack size down and increase the number of times, you get moved to another table. To me it feels a little crazy, when after 45 minutes only a third of the players have taken their seat, but I guess, its a lost fight.
poker sites are not going to reduce late registration, because it would hurt their profit to do so.
I prefer a structure, which is not to fast, but sometimes turbos can be fine. The ones on
888 Poker have 6 minutes blind intervals, and there is a decent amount of play in those. The turbo SnGs on Stars is a bit to fast for my taste, but they are a good option, when you dont have time for a slower MTT. So I do sometimes play the 45, 90 or 180 man turbos on Stars, but they are not my favourite form of MTT. Its a bit to much push or fold and to high variance for my taste.
As for bountys and add-ons I dont think, they add to the playing experience, but both formats are excellent for making money. Bountys appeal to rec players, and they often over adjust completely, which allow you to pick up a lot of easy chips, when you have a good hand at the right moment. I have taken out 4 players in one hand with AK in a 4$ bounty on
888 Poker, and none of them had a premium hand.
Add-ons are also very profitable, because they lure rec players into playing above their usual limit. This mean, that a 2,2$ R+A is usually must softer than a 5,5$ normal tournament with the same payouts. I have made a lot of money in the 1,5$ and 2,2$ R+A tournaments on 888 poker and consider them some of the most profitable tournaments on the site.