Yes I played slot games only as it is the game that I like most. I played 2-3 different slot games only anytime I participated on the contest. It is very rare for me to change switch from one slot to other slots, at least I will spend few hundred spins on each slot. If I have to use buy feature, I will buy 5 times (max) in each slot game. I know you like buy feature as well, dont you?

As I have seen your username several times under the High Rollers tab. If I remember it correctly, you like Sweet Bonanza nad as I know your were even higher than what I used to do.
I haven't done maximizing how much will I spend to those buy features. I do like buying feature much. However, there are few times that it really caused my balance to be depleted very quickly (all of my winnings for the whole week are gone). I really think that is because I didn't limit myself on how many buy features I will buy even though I know the possibility that buy feature lose streaks is still possible. Greediness indeed.
So from that there must be a maximum limit on how many features that must be purchased, I also sometimes experience the same thing when several slots that I play up to hundreds of rounds haven't gotten a big multiplier then that's what I do with the buy feature, but if it's maximal I will end it. I know that the victories we have saved are only used up because of ambition, indeed this often happens but if you think about it, you can control it well.
Slots sometimes make us forget ourselves with the balance that we have stored up so far, because we are too ambitious.