I have never used simplified ALPS, which I gather are most of the currently available ALPS switches.
I can compare my memory of using complicated Blue ALPS on a Northgate Omnikey Ultra in the 1990s and early 2000s with my two-week-old Filco MJ2 Browns.
Both complicated blue ALPS and Filco brown have a distinct sound and a two-part key feel. Both can be hit hard or softly, and for me the softer touch is faster but is also something that I can only achieve when typing quickly with my hands in proper typing position.
The Cherry Browns have a lower activation feel than an ALPS blue, and are also a little quieter. I think, and think is the operative word here, that Cherrys have a lower impact than the ALPS if I let my fingers decelerate before hitting bottom, but my faulty memory tells me that the ALPS had a softer landing when bottoming out. I am doing less writing now than I did then, but my sense is that a Filco MJ2 brown is a little faster than the Omnikey Ultra Blue, perhaps because my fingers are short and the key spacing on the Omnikey felt a little larger than usual.
More to the point, both keyboards are crisper than rubber domes and both keyboards are something that my fingers easily adjusted to.
Given the choice between shopping for a used or reconditioned Omnikey with ALPS Blue or buying a new board with Cherry Brown I went with the Cherry Brown without hesitation, in part because the slightly quieter keys and much smaller deskprint better suit my current needs.
If you are thinking about going from Cherry Brown/Blue to complicated ALPS then I think you can expect a firmer-feeling key, a similar break partway down the stroke, a very little more feeling of lateral rattle or movement, a louder key with a lower pitch, and (possibly) a slightly softer landing at the bottom of the stroke, and possibly a slightly slower typing speed.
I can't say a think about simplified ALPS.
I hope this was helpful and did not contain too much nonsense or faulty memory.
