I would definitely agree that they should not be compared. I think I also said that somewhere in one of my posts about it, but yeah. They're so different fundamentally that you can't really compare them. As for the MMO aspect of both of them, I actually felt completely opposite about Log Horizon. For me, it seemed like Log Horizon was basically a fantasy world simply given the name MMO as a sort of eye-catcher and a basic set-up for the plot. The fact that the People of the Land are no longer simple NPCs, the fact that they use skills with their bodies now rather than a menu, and the fact that cooking and crafting and whatnot no longer follow the old MMO paths made it seem much less like an MMO and more like a real fantasy world to me, which I think is part of the point of the show's plot. There's also never a legitimate reason given for how they arrived in that world, leading to a deducement of "magic," as one would expect from a fantasy world, rather than technology, as one would expect from a VR anime. The only real MMO aspect Log Horizon retains that is noticeable to me is player levels/stats and raid battle strategies. I agree that you could also take the MMO out of SAO and it would work fine as well, with some adjustment to the character's personalities and backstories, but to me, it seemed more determined to stay on the MMO path. The anime doesn't portray it as well as the light novels do (Actually, I'm having trouble thinking of a time they even speak with an NPC in the anime), but NPCs in SAO all have set dialogs that must be triggered by certain "keyword" voice commands in order to carry a conversation with them and receive quests, much like NPCs would be expected to in an MMO. The levels/skills thing is basically the same as Log Horizon, so there's no real difference there, but I suppose the items SAO introduces, such as teleport/healing/corridor crystals, healing potions, and map data also make it feel like an MMO to me, alongside the pet revival quest and whatnot. Log Horizon had items and quests too, but we see very few items, and the majority of the quests were major requests from the people of the land, such as "The Return of the Goblin King." It felt like they gave events like that the title "quest" purely as a reminder that it was once an RPG. Those are things you would expect any person in an actual fantasy setting to request help with, as they are actually a threat to the world, unlike SAO's pet revival flower quest for Beast Tamers or the "Sick Daughter" quest for a new sword on floor 1 (In the LNs).
Tl:dr, I felt like Log Horizon was purposely steering itself away from MMO and towards a true fantasy world, as a large focus of the story is that the world is their "new reality." SAO, on the other hand, seems to be much more dedicated to the video game theme, as seen by the numerous MMOs introduced in the arcs. Neither one of these paths is any better or worse, but it's just the way I saw things.