In my opinion, Kamaka ukes are the only ukes that you can (not at all saying you should) buy sight-unseen. The craftsmanship and quality assurance that goes into each ensures they play like gold. I've played very many Kamaka ukes through my short time on this earth and they were all astounding.
The same thing cannot be said about KoAloha, in my opinion. Just the other day, I went to my local music store and found a strangely high action on one of the KoAloha tenors.
With regards to Kanile'a, the models I have sampled were all pretty consistent but the overall feel is very different from that of a Kamaka or KoAloha or 'lesser quality' brand. Different doesn't mean worse. With Kamaka and KoAloha, you get a very warm and full sound when playing, partially due to the stock strings of each. With Kanile'a you get a very sharp and resonant tone throughout the whole instrument, again partially due to the stock strings. This 'x-factor' (lol) makes Kanile'a ukulele very, very unique and in my opinion, need to play before you buy.
In my opinion, if you are set on getting an ukulele sight-unseen, go for the Kamaka. If anything, getting a centennial model could mean you could flip it next year and sell for MSRP (assuming they're all sold out by next year, which I think is likely). A lot of people have voiced their recommendations towards this side of your decision and a lot of people have voiced their concerns towards the Hawaii trip souvenir decision and I would follow suit. It will be highly unlikely you will even find an HF-3 for sale in your short time here.
These are all just my thoughts so take it with a grain of salt. Hope I helped.
Go for the 2016 Kamaka!