Really kinda wish the slot machines in Borderlands 2 had a ten spin option. Standing there pressing the button over and over on each - that's not really gameplay. If you had an option to spin ten times and take the best results (along with any bombs), it'd be more akin to gameplay instead of - well, whatever using slot machines is classed as.
Otherwise I've finished the game and it was quite engaging even in single player, right up to the end. Not sure how they did that/what math they used that's different from last time. But it seems even guys who are lower level than you, if you run in they will chew your shields apart. Maybe apart from bullet spread over distance, they do more damage closer up? Not sure.