My main problem with chillaccino is how similar it is to ambipom. same typing, abilities, (pickup and cute charm are useless) and very similar stats make it so that the only distinction is movepool
a side by side comparison of stats:
Chillaccino: 75/95/60/65/60/115
Ambipom: 75/100/66/60/66/115
none of their base stats are more than 6 apart, which is quite remarkable. Chillaccino only has more sp. Att. which he probably won't use too much anyway.
So what really Sets them apart is movepool. and while Chillachino has numerous multi-hit moves to abuse, ambipom has fake-out, taunt, and other staples that make him an effective lead.
tl;dr: I think chillachino is useful for hitting hard with multi hit Attacks, while ambipom is still a superior lead. but I'm not exactly a pokemon authority, so my thoughts aren't law.
Totally posted almost this exact thing a week ago. lol. Literally, go back a page. Guess that means I agree with you though.