A bit harsh on Maian and Stefan, but I'll give you the rest.
I'm convinced this is Ott's to lose.
Stefan's song seems an Avicii's "Hey Brother" B side with some more country in the verses and a way less memorable chorus, imo. Not a bad song, but nothing really impressive.
Maian? Yeah, I can't say I dislike Meeletu and I can see why people think this song could win Eesti Laul, because it's a contemporary sound and it could leave an impact, but I really don't know... Estonia had mixed results when it came to native language songs in Eurovision, and I don't think this song has the same potential of some past Estonian entries, like "Randajad" or "Kuula" to name a few, to really shine on Eurovision stage.
I really don't like the other songs in this top 5: Interstellar is really basic and really safe, and it's up there because Stig sings it, let's be honest. Champion has just won a nomination for the "best clichèe chorus of the year" in my books, giving me Australia Jesc 2016 vibes all over ("We are Champions just screaming out we are..." (cit. Alexa Curtis)) mixed with standardized Mello sound from mid 2000's. Fire? I mean, come on. I call this the "Eleni Foureira syndrome": you see a girl singing, you see some fire, you see some dances, so it's a masterpiece, right? Wrong. Fuego at the time was something new at least in Eurovision. But trying to copycat something successful doesn't mean you will succeed. I hope this song will stay in Estonia, I said it.
Ott? Yeah he is the clear favourite, imo. Aovalguses is a ballad, full stop. He has great vocals, so he will certainly deliver, we know it. Did I prefer this one to Kuula? I really don't know. What I can say is Ott is not my number one: my favourite is actually "Little Girl" by Merilin Mälk, a simple soft ballad, with a cute little lyric scheme, which I actually find very pleasant to my ears. It's not the most innovative song of all time, but I really enjoyed it. Like I enjoyed "Remedy" from Elina, as I said before. Because it's totally different from "La Forza" and I think it is more accessible to the audience than "La Forza". I actually like Remedy more than La Forza.