If you like to run fast, you have TONS of choices going back over 80 years. If you like trains that run slow, especially on sharp radius curves, your choices are few.
One of the things that was instructive to me, was seeing the video feed from a video camera car pushed ahead of the locomotive. At anything faster than 15-20 mph, it looked like I was riding a roller coaster! Talk about barf-bonnets! Sure, some prototype trains went 75-80 mph (and most 3-rail locos are geared to exceed that by a lot!) But NOT lurching into sharp un-eased curves, 22-degree crossovers between mains, and short straightaways. I won't even talk about the 5% grades because I didn't have any.
They're your trains, so run them at the speed that makes you happy. MTH's departure will leave room for another competitor in the marketplace. If that company builds slower-running versions of the locos I like, I'll buy them, and sell you the ones I have now at a discount ;-P