I can't speak to Tech Sights as I don't have them (I'm sure they're great, just don't have them). I do, however, have a set if Williams FireSights (fiber optic) for my model 60. They were very easy to install (after unscrewing the front and drifting the rear out). The front screws on in the same place as the factory front, and the rear slides into the drift dovetail on the rear (and is held in place by a set screw. Another screw sets elevation.
They are likely slightly less accurate than Tech Sights, but the doggone things just JUMP OUT at me, making acquisition a lot easier (the downside is that admittedly a target at 100 yards is pretty much hidden behind the front sight). As always, your mileage will vary.
Hope this helps.