I wore flips for my first 6 years riding, and am now finally comfortable enough with a helmet to have moved to full face for the last 2 years. Full face are, on the whole, lighter, quieter, and safer.
I too look at SHARP ratings. They are a bit hard to translate to US helmet purchases as only AGV, Shark, now Schuberth, and a few others actually bring the exact same helmet over. These brands tend not to be in wide distribution in our market.
But there are some generalizations you can make from the SHARP testing: Last I looked, no current model flip was rating a 5 star (top score). Flip up helmets do flip up in crashes, and some do it quite regularly, others are better.
The Schuberth C3 is available locally for $700, but only scores 3 Stars in SHARP testing, has a ridiculously uncomfortable chin strap (for me...although I see the complaint does crop up a fair bit on the internet). The weight is fair, comparable to many full face, and the SHARP found the chin bar stayed mostly closed (97% of impacts).
The Shark scores a 4 star, but is ridiculously heavy and has a clunky mechanism. I gave up my Shark RSR2 after only a year due to the face shield coating peeling off, the face shield mechanism breaking, and a comfort issue that developed over time. Personally not inclined to go back to Shark.
I had the HJC Symax and before that it's predecessor, CJ-Max was it? They each lasted me about 3 years. In both cases the mechanisms got clunky and hard, the liners got overly compressed and the helmets were both reitred for eventual loose fit. However, at the price 3 years might be a pretty good deal. HJC does not cross certify... SHARP tests different helmets than we get in the US, but the mechanisms seem similar.... HJC has very low (40 and 47% of impacts) ratings for chin bars staying closed, which I find worrisome.
Shoei... I can't generally wear them as their chin bars are too close for me...
To me, now that I feel comfortable with a full face, I just don't feel the need to go back to flip. I used to feel that with glasses I couldn't wear full face, but now I do it. Works fine. I just don't see the advantages of flip any more.