Worth upgrading from 3b+ to a 4 for PSX and below?

[chubsta]

I only really play older systems, SNES, Atari, Megadrive, TG16, arcade and a few bits of PSX, I have no interest in Gamecube, Dreamcast etc.

Would I see any difference in upgrading to a Pi4 from my 3b+ -

I run my roms from an external spinner HD and sometimes get lag in the ES and system menus which I am attributing to the fact that the HD is only USB 2, would that be correct? If so, would I see an improvement with my current HD due to the 4 being USB3.0, or would a move to an SSD on a 4 show big enough improvements to justify the cost?
Most of my time is spent running games in Mame, would I see any noticeable improvements in, for instance, Gauntlet Legends?

[Darksavior]

@chubsta Arcade games are still hit or miss. I'm not sure if gauntlet legends runs full speed. If it doesn't, the dreamcast port should be full speed.

For snes, a pi4 allows you to use the latest version of snes9x. Which means more accurate/less buggy emulation and the ability to use msu1 audio.

For psx, a pi4 allows you to use the double res feature without the buggy speed hack.

I use the pegasus-frontend and it's much faster and smoother on a pi4. You should get some speed up with usb 3.0.

[chubsta]

Thanks very much for the detailed reply, it seems like the benefits will outweigh the pretty minimal cost.