They're both great choices. I really prefer Anbernic when it comes to hardware, but I lean toward recommending the MM+ based on the software. Onion OS is fantastic, and the options for the 35XXP/H aren't on the same level. muOS is what I use on my 35XXP, but it's not quite as streamlined.
If you want analog sticks, the choice is obvious. Just depends on which PS1 games you want to play. Personally, I prefer playing 3D PS1 games with an analog stick regardless of whether they're required.
I will say, however, that I'm not a fan of playing DS on these 4:3 devices. You have to set up a button to swap screens (and there's no touch functionality), which I find cumbersome. Really prefer a 16:9 device when it comes to DS so I can have both screens up at once. Not everybody cares about this, but it's something to keep in mind.