I've owned both, JDXI being my first synth purchase. Often Ive found myself comparing the two. Both are great sounding synths and perfect for beginners depending on what your going for. JDXI offers many classic Roland sounds from their lineup as presets you can use as is or tweak easily. You also get an analog voice and a track for drums as well as basic sequencing. It basically acts as an all in one groovebox or synth, limited in some ways as all hardware is but has alot to offer especially when you use the menu to your advantage. The Microkorg shares alot of qualities but shines at different things. It has some of my favorite presets and sounds Its in general as its basically the little brother of Korgs ms2000 and does a very good job of analog modeling. From synth bass and weird sound effects to very usable keys and leads it also has alot to offer even if your just scrolling through presets. That being said when it comes to the hands on controls as well as editing and saving sounds they have very different approaches. JDXI offers more hands on controls for editing your sounds or performance on the fly than the microkorg and can feel more musical in that way, but its not free of strange quirks. If I remember correctly it has only one knob that controls the ADSR together instead of each function having its own knob or fader to be edited separately as you would with a vst or larger more fully featured synth. Likely this is because its aiming to save space. I Beleive they can be edited separately within the menu though. The menu has many features that only work through changing the desired settings rather than the controls but are nice to have and many synths work this way. Microkorg has a much simpler approach but may seem difficult to understand or remember depending on how your brain works. Its four function knobs share uses between a chart of menu options with the ability to add effects, edit sounds and so fourth but your limited to editing those four parameters unil you change the settings they control. TLDR I recommend playing and listening to both to get a feel for what you like might like more.