AB2 on Genesis plays about the same as AB1, which is still great gameplay if you're like me and enjoy 1st person perspective shooters.
AB1 on 32x is arcade-perfect. It plays fast, though the graphics are only as good as the 1980's arcade they started on. But that's good enough for me.
AB3 on SegaCD is my favorite actually. The intensity is somehow just upped a notch compared with AB1 & 2. Especially with the Cd-audio tracks, and the audio "whew" that accompanies near-miss missles makes you feel more like you're really evading death. The intro animation is NES quality, which is kind of a disappointment. They could have used some nice FMV like Tomcat Alley for the intro, or some 3D polygon F-14 like silpheed or starblade.
The ingame graphs are also rather subpar for SegaCD. The earth and sky are just 2 colors and sparsely populated with a monotone building. No texturing, which itdefinitely could have done (e.g. thunderstrike or soul star).
But it's the gameplay and audio that really makes up for the graphical strikes. The best part is that you can choose either in-cockpit or behind-the back. And you can also choose reverse or normal up/down control. I personally enjoy in-the-cockpit flying/racing/shooting much more than 3rd person. So I think it's a blast to get to play Afterburner in-cockpit.
Oh, and I should mention the other great feature. You have a free-motion option. It also supports the original AB-style roll technique (where you turn right, and then left fast to execute a roll). But it's really fun to turn on the free-flying mode, and then you get to fly sideways and upside-down at will.
And then turn those missles on auto-fire, because they never run out!
And you can see your damage, like bullet holes in the cockpit window, and smoke and flames out the back (you're auto-put into 3rd person mode temporarily when you get a bogey on your tail).
I have to say. With free-roll mode, in-cockpit, auto-missles, and CD-audio, it's really quite a blast to play. And you can complete the whole game on hard in under a half hour, so it's a nice game to whip out when you've got a half hour to burn.
AB3 is actually a descendent of G-Loc, not afterburner I think. But I've played G-Loc, and while the in-cockpit is nice, the gameplay kinda sucks. They probably renamed it to AB3 rather than G-Loc 2 because afterburner is more popular, and it really is kind of a mix of the two design wise.