I would play or possibly use some 2nd edition elements... if I could find it, wherever it is in this house, LOL.
having said that, I'm not going to really compare the 2nd and the 4th, but will say, that the 'polishing' of the 4th makes me favor it.
I can see where 4th Edition Dragons could be played in 2nd Ed, per Doma's comments.
I am a player who uses all expansions, but switching around the use of the Dragon 'inlay board' from the 4th.
We occasionally do not use the board, but every other feature of the Dragon expansion for 4th. We mostly use the board, but only the Realm side. We haven't played the Dragon Tower side of the board, not sure if and when we will.
Like Doma says Players who use 4th Dragons may use some house rules. Ours is pretty simple.
Mostly a delay of the scales being pulled on each players' turn. This seems to be the main complaint, that Dragon scales proliferate too quickly (but the design idea is to force you to get up to the Inner region and challenge sooner).
So to delay the pulling (and it is arbitrary and hit and miss, btw) we do not pull scales unto after the first Dragon is encountered by any player, from any of the regular Adventure decks.
We use an in-story kind of reasoning. That the Dragon Lords are mostly not paying attention to the realm - until one of their own is encountered. Works for us, and as said above, it may not happen right away or it might anyway depending on the draw of the cards.
This still leaves possibilities for those who either want to continue to slow scales, with certain characters having the ability to replace the drawn card with another card. So the Prophetess and similar characters have helped "foresee" the Dragon menace and help contain it (for a while).
In our last game I used a spell that voided the card being drawn - since it was a Dragon. Things like that help in the delay of pulling scales, if that is how you want to accomplish that.
Recently we thought of other ideas, more of a limit on scales.
1) If you use the Blood Moon set's Day/Night dynamic, you could say that Dragons scales shedding occurs during the day because they don't journey much at night (have no idea if there is any traditional Dragon lore on that, and we have not agreed to it, ourselves, btw)
2) Exception: When using the City, consider that Dragon's avoid the City during the day (at least) because a City's defenses would possibly be something they would avoid (again, "in-story" reason).
but - at Night, the Dragon's are possibly attracted to the City's fire/lights, as Dragons may be. Therefore, in the City, scales are only pulled at Night.
As I said we haven't agree to this, but it kind of has it's own story for the game, and a twist I find interesting.
Don't be afraid of 4th Edition anything and consider moving as you can, to that 'platform'.
The only thing I miss from the 2nd, actually, is Timescape (but my wife/coplayer doesn't miss it very much at all).
So I'm the rarer player. I like Dragon (enough) in the 4th, whereas many seem to not.
I would like a 4th edition version of Timescape, whereas many seem to not want that at all.