It seems that the overall opinion is that things are faster in FS2, thus making the FS1 Dragon more slow and cumbersome, wich means "easier" to track, and eventually kill.
Don´t get me wrong, i have indeed played the official FS1 before. I never finished it, and i can´t remember wether i found Dragons or not, back then. My PC was a piece of defecation then, and the graphics on it sucked big time, so i didn´t get too much excited about playing it to the end. Now the port, that is worth playing!!
As for the engine acting diferently, i really don´t know. It has been too long a time for me to compare between them both.
What i have figured while playing is that the player ships are way too ****ty in comparison to FS2. I spend most of the time waiting for my guns to recharge, and all the ships feel like you´re flying a cap ship, instead of a fighter. They are so slow turning, that it´s almost pathetic...
A plausible explanation to why people think the Dragon was harder to kill in FS1, could be because people were still "learning" the ropes of the game, while in FS2 people are already experienced pilots making it seem easier, when
it´s just you that changed, and not the game.
And, of course, this all depends on each individual´s skills at handling the game, isn´t it?