Exagear is definitely smoother, because it’s not an emulator, but a (crude) W.I.N.E port. But it’s so woefully broken in many aspects, I don’t ever use it.
Magic Dosbox on the other hand, being a real emulator, needs much more processing power, but offers much better conpatibility especially for DOS games.
I compared performance on my old Note 4, with Diablo 2. It was unplayably slow in Magic Dosbox, but sort of worked in Exagear. Sadly, the Exagear controls were so poorly designed, it was a PITA to play.
Now on my S7 Edge, Diablo 2 runs perfectly smooth in Magic Dosbox, so there’s no need for Exagear anyway.
What you can do is download the Doom shareware v1.9, and execute it with “doom timedemo -demo3”. The resulting realtics score (2134 gametics in xxxx realtics) will show you how fast your cpu can run Dosbox.
S7 (Exynos 8890): 650 realtics (~Pentium MMX 233/AMD K6 300)
Note 4 (Snapdragon 805): 2200 (stock), 1400 (heavily tweaked)
Galaxy A5 (Exynos 7880): 2000 realtics (and I won’t tweak my wife’s phone, she’ll murder me if I brick it?).