I have never used the Midnite units... I wanted one for the longest time, like the MPPT KID, but after I learned about the Victron Smart units I basically use that exclusively now and I think they are great units. That said, both should be do lithium just fine.
The Victron units have 100% user defined settings which was a big selling point for me.
For lithium, as long as you can disable equalization and temperature compensation as those are more for lead, you should be good to go. I set absorption as my max charge voltage, and just under that because really you don't need to float lithium cells. You don't have to worry about chemistry or the pre-set options for it because you can just customize all the parameters likecharge voltages to make sense for your battery setup.
I manage my entire Victron controller from my iPhone/iPad, nice user interface and good trending / logging of data.