I am not asking for a solution to punctures, or about the nuances of ride quality with the various solutions. I am asking whether one method of reducing punctures has been proven better than others through scientific testing.
I often see people online using tubes with sealant rather than tire liners or puncture resistant tires, and wonder "why?" The slime is messy, can clog the valve, weighs more than liners, and does nothing to actually prevent a puncture, but rather waits until the puncture occurs to go into action filling it and (hopefully) coagulating in the hole. I've read that this really only works on small holes, too.
Purely anecdotal evidence:
I've ridden for the last eight years on the same route during my commute. I started with tire liners on regular tires, then went with Continental Gatorskins (Kevlar belted), and am now on my second set of Vittoria Randonneurs (double-shielded), and of the three setups, only ever had punctures on the Conti's -- at least two flats per year (grrr!). Zero flats on the Randos in nearly four years while laughing my way through the fields of glass. I see Schwalbe Marathons recommended more than any other brand, and while many say they've never had a flat with them, I also see some cyclists posting that they've had flats with those, too.
It just seems to me that there's no competition: double-shielding wins, IMO. It's less hassle that liners or sealant, and just as protective as liners/more protective than sealant, and generally weigh the same or less than sealant-filled tubes or tire-liners. Not to mention the cost factor over time.
Can someone explain the advantages of using liners or sealant over puncture-resistant tires, specifically relating to resisting punctures? Have any scientific studies been done to compare the three methods?