About 6 years ago I bought a Canadian registered Glock 26 and ordered up a 4 1/2" Fed Ord SS ported barrel for it from Brownells [ $ 90 US ]. I fitted the longer barrel to the Glock, then attempted to get it re-registered with the longer barrel. It only took about 6 months before they decided it WAS doable, but they demanded I surrender my original short G26 barrel as part of the deal.
I really liked the way that G26 balanced and shot with the ported longer barrel, but eventually arthritis forced me to give it up and go back to the full sized grip of the G 17.
I still have a spare extra length "legal" SS Oly barrel that will fit either the G26 or the G 19 [ but NOT the G 17 ], and perhaps one of these days I'll get a G 19 to put it in. Until then, my G 17 C is doing just fine.