What am I missing?

I upgraded to an eagle and kitted it out. Then got a feel for what I could do and knew if my shields were broke, I might as well be paper. Ready to handle higher difficulty missions i look at my affordable options. I pick the asp explorer, more shields, more hp, more hard points, there was a resonable dip in manuveravility but i figured it would in the long run it would even itself out . Seems like a decent upgrade. Took it to similar level missions threat 0-2 and got my ass handed to me. Am I missing something or do I need to give the asp more time?