[Baalz]

Hmmm, I'm coming at it from the other angle having played Mictlan extensively and just picking up Lanka. Just starting out with Lanka, but here are a couple things that I seem to be missing coming from Miclan.
1) Bloodhunters are 50% more expensive
2) Everybody complains, but I like dominion pushes through blood sacrifices with level 3 priests and easily forgable jade daggers.
3) No easy way to spam "rain of toads". Priest king + armor of twisted thorns = very scalable ability to shut down enemy fortresses.
4) Mictlan national summons ROCK. Haven't got the Lanka ones yet so can't really comment, but the Mictlan ones are hard to beat.
5) No recruitable blood-3 mage (without hoping for lucky randoms). This is important because you need blood-4 to forge brazen vessles, and one empowerment is much more palletable than two. Plus, once you've got a brazen vessel with Mictlan, you can give it to a priest king, who forges an armor of twisted thorns, who gives that to another priest king, who forges an armor of twisted thorns, now the original forger gets an armor of twisted thorns in addition to the brazen vessel and can forge brazen vessels, etc. etc., so it is relatively cheap to get as many blood-5 mages as you care to (priest of the sun + 2 path boosters), and there are several very good blood-5 spells which are very suitable to spam casting (ritual of the five gates and infernal disease come to mind). Plus, your blood-5 mages can rejuvinate themselves so the old age issue isn't that bad.
6) Flying sacreds. Eagle warriors have saved my bacon on numerous occasions.
7) No easy way to summon Ice Devils (priest of rain + water braclet + brazen vessel)
8) No easy way to send horrors (priest of moon + astral cap + brazen vessel)
9) Less reliance on random pics. With Mictlan, I can adjust my strategy to what my opponent is doing. With Lanka, I'm more stuck using whatever happen to have with my random magic paths.

Don't get me wrong, Lanka has plenty of advantages, I'm just listing the ways Miclan seems to be better to me.