I have both the Legend LX and the Mikron. I love both of them. I really like the hose on the Mikron. With the Legend LX, I get a little "hose push" as the hose comes over my shoulder. The Mikron has the new braided flexible hose and while it becomes more rigid when pressurized, I don't get the push.
Now, the Legend (or LX) is a BETTER regulator. It has an overbalanced diaphragm and is pneumatically balanced, which basically means that it will breathe better at deep depths, with a cylinder that has lower pressure, or when the diver is breathing hard (strenuous diving or two divers off the same cylinder).
The Legend does not have a user adjustment knob that the Legend LX does that allows you to loosen up the cracking pressure (the ease of breathing). The Mikron does have one of these too.
Both Legends have the ACD which is the auto closure device, which closes off the first stage when it is removed from the cylinder. The Mikron does not have this.
The Mikron is very light, so if you travel often and are concerned with the weight limits, you can't beat this regulator.
I know you wanted the opinions on the Mikron and Kronos but I don't have the Kronos and someone else brought up the Legend.