UniPCemu can handle Pentium II with accurate CPU(without FPU/MMX though), 2D acceleration(ET4000/W32 with actual CRT emulation(no physical effects though, other than raster emulation for any video mode you can program (using x/y precalcs, think like a rails where a precompiled 'program' for horizontal or vertical coordinates that's executed each video cycle by combining the bits from both into a rendering signal (vblank, render pixel) executed in parallel))) and other 90's hardware. Although it's still slow to do more than 300KIPS CPU instructions/second on an i7(mainly due to high RAM translation throughput for instruction and memory fetching).
PCem has that as well, perhaps hardware accelerated, and at full speed or too fast, but is missing the accurate CRT like UniPCemu has afaik (the same with UniPCemu's other cycle-accurate hardware). Although it's 8088 might be more accurate if it's using Reenigne's latest 8088 reverse engineering on that (UniPCemu is close wrt to that, with a few instructions being slightly inaccurate still(only 8088MPH's initial cycle count and raster bar racing effects)).
Dosbox is just made for less accurate stuff, mostly employing hacks for edge cases (instead of being more accurate).