IMO Double Dragon II on the NES is severely over-rated.

Other than it making up for the fact that the first entry didn't have a 2 player simultaneous mode, there's nothing about it that I really enjoy.

In comparison to its arcade counterpart, it's painfully slow, it's monotonous (though most Double Dragon games suffer from that) and as you touch on in your review it's very very easy even on the hardest setting.

I know that it's not the common or popular opinion, but I prefer playing through Double Dragon 1 on NES in single player mode where challenge's sake is concerned, and for 2 player beat-em-up action on the NES I'd much rather sit down with a friend and do a run-through of River City Ransom, Battletoads or TMNT III.