1. You forgot to mention one important advantage offered by printers that use solid ink with thermal sublimation: photos are said to last for 100 years (that means no color deterioration due to sunlight!), they are protected by the 4th and final laminating layer against water spills and fingerprints (yes, that's right)!
Don't know if it's really 100 years, but the fingerprint "protection" alone makes it a sweet deal.
2. The Epson and HP models aren't exactly portable. They are actually big if you compare them with Sony and Canon, and especially the Polaroid (WOW). A better term would be dedicated photo printers, in my opinion.
3. The Sony FP95 tops at no.2 regarding print time and you call it "mediocre printing time"? If that's true, then what about the others? You haven't even mentioned their performance, except for giving us the values.
I don't want to tell you how to do your job, but if you use only "mediocre" and not "worst" or "best/second-best" use it for the lowest performer.
I have to say I was expecting an answer from the author, but now I don't thik it really matters. Shortly after my first comment I decided to look into the printers in detail. The HP A626 you talk about in the articke is actualy a A826.