Neither is foolproof or bullet proof.
Room light can mess with IR detection.... a light about to burn out more so. (worst were incandescents about to burn, then any florecents, then halogen (LED room lighting was not in use, placement is a factor too)
I do like IR a whole lot, I just know them better than most folk from non-train applications.... great product; but everything has limits. Not a bad type of circuit to begin learning about electronics more deeply with either. You could make one too, but the result likely would be slighty worse until you learn to aim, sheild, and adjust well...not to mention the trackside electrical box look is darn cool.
Pressure contactors, I prefer older ones. The leaves seem thicker, the points foul less (file/sand/bend flat,clean), the mech. hangs less once old, adjustments work better (even after trying many spring rates on newer ones, adjustment works best on the older.... I use 6, 3 old, 3 newer(more plastic)
I also made one with a 2" strip of copper bent to a mild convex (up), just under a rail, and stuck a spring under a tie. Worked even better, but was on a temporary track.
Isolated rails can be made on most track. For tube track, cut a box top off your box of Wheaties... pry up the tie hold downs on an outer rail, insert cardboard, close them... it should look like the center rails isolation now. Plastic pins replace the metal pins for that rail only.
As any metal wheelset travels over it, one wheel picks up the non-isolated outer rail and connects it to the new isolated rail via axle & other wheel (like a switch ) A wire from there, and a maybe a wire from center (depends on acc) now go to the accessory.
Some accessories won't like Iso-rails though. The pressure and IR triggers have more isolation from the actual track, and doesn't take away a rail as a power delivery . Dirty wheels and track won't work as well on iso-rails. Plastic wheels won't work at all on Iso-rail. (2rail and cheaper cars use plastic or at least a plastic insert in the wheel hub to keep their outer rails isolated as each is a separate power leg.... cheap cars....are just cheap.
I think the IR also contains an after trigger "on time" adjustment (or off).
I don't have an overall preference, except that I don't really like board work anymore. I'm more of a electro-mechanical fan than a tech chaser. I've found it more reliable... mileage may vary.
Stans point is spot on.... the more you tell us in one thread, the easier yes, no, or "like this" becomes. Options are vast without specifics...and sometimes with them too 
Oh, wood tie track GarGraves/ Ross, maybe Atlas(?) and some MTH already have isolated rails... when you install it you must connect them if you want them to both carry power.(makes for easy radical customization, or simple set up. It covers everyones plans, just takes a little effort... great track ). You can also buy iso-rails in most brands, even old tubular... it's just soooo easy most folks do it themselves once they understand what is needed.
