These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Fan Dumb: While Gabu and Mei certainly has an ambiguous relationship, it can still be taken as just being that of True Companions. However, lots of fans will tear you down should you ever suggest such a thing. THEY'RE MADLY IN LOVE, DAMMIT!
It Changed, Now It Sucks: The cartoon series. The fact that it's CGI and Mei is a girl did not help at all.
Controversy exists over the homoerotic overtones of the anime. Word Of God confirmed that, in actuality, Mei was always intended to be a male character, but was written in the children's books as gender-ambiguous so that he'd appeal as much if he were female as if he were male. The film merely restored that gender specificity.