Kashrus =/= nutrition. Do you get more gan eden for only eating from "top" hechsherim?
I don't know. But I think eating the Top Hechsheirim has to do with many factors (in no particular order):
1) Your general approach to Yiddishkeit (Are you more Brisker or more Modern Orthodox)
2) Your Minhagim
3) The area you live
4) The type of people you associate with/spend time with (Yeshivish, Balebatish, etc. etc,)
5) Your financial means
6) What your personal Rav holds
7) What your spouse wants
8 ) How often are you on the road/ not eating at your own house
9) How much you've seen in the field of Kashrus
10) How much Yiras Shamayim you have