I'd prefere a 16" on the 550xp/2253, just because of the balance - but each to their own!
I just got to ask. So you have borrowed or owned a 550xp or 2253 and made cuts with 16" to know how the balance of the 550 saws are?
I have owned and cut with 550 545 and part of the reason why I prefer it over the 346 saws.