Most ppl prefer light armor types because they bare no penalty to run/walk speed. Best choices would be Mage Plate, Dusk Shroud and Archon Plate.
The disadvantage of Mage Plates is its lower defense value as an exceptional armor in comparison to elite armor bases. But since Enigma grants a flat amount of defense instaed of percentages, the diffenernce in defense stays just the same as with the base types.(/which is only around 260 or so compared to an archon).
The advantage of the Mage Plate is just its low strangth req. Enigma grants a huge amount of additional STR, and many ppl just dont want to exceed the value demanded by their gear (which often is 156 for a monarch), so they can put the spare points into VIT. Archon has a req of 103 on its own and with +STR per charlvl from Enigma u would easily achieve 170+ STR in the early lvl 90s.
If u need more STR than that anyways, then better take the archon plate.
And be aware of superior bases. While +% def adds greatly to the flat def of enigma,. the repair costs can be annoyingly high everytime.