Eh, what's that sonny?
Seriously, I remember those games too. While they were good in their day, they feel far short in immersion and in simulation accuracy.
I couldnt afford the very high cost of the online games back then, and I've only been playing AH for 2-3 years. I had always done boxed sims, and did my best to learn the combat techniques -- but with only limited success. In AH, that has turned around.
The boxed sims back then were obviously graphically inferior, but the greatest difference you'll see by far is in the opposition. There is simply NO comparison between an artificial opponent and a human one, no comparison whatsoever. In AH the greatest challenge is in adjusting to the unpredictability -- the enemy that prooves to be plain dumb one time, while the very next one may be devilishly skilled. (worst of all are the aces who dangle themselves as "I'm a Dweeb" bait before they snap around and ream you.)
Flight modelling is radically different as well. The processing power now available allows for a huge range of calculations to be done on the fly, so planes behave differently depending on fuel loading, rotational forces, disruption from control inputs, etc.
Aces High's designer has chosen the path of "fun accuracy" -- he tries to make the flight model match every piece of performance data available, and continues to add new aspects to the flight simulation, but he stops at the point where fun turns into work.
Best of all is the community -- a great bunch of guys. I encourage you to chat, to post, to talk with the players on all sides. There are lifetime friends made here. (For example, my squad CO has hosted several trips our Finnish member has made to San Franciso, after years of online friendship.)
This is NOT a point and shoot game, and its not one you can expect to mastter in a few weeks. There are guys who've done online sims for more that a decade -- and who know their stuff flat out. The game is also deeper and more rewarding than any this long time computer gamer has ever played.