I bought four of these stair-gates / barriers. I believe the hinge design has changed very slightly since the version which may have altered the fitting process but otherwise the current product looks identical. We bought these to separate rooms without closing the doors - for ventilation, light & sound to pass around our apartment - we have no stairs to protect but the instructions for fitting them to stairways seemed clear enough.
The major advantage of this design is that it has an excellent range of width fittings - far more than most other products we looked at. As we live in a building with non-standard measurements these were a sure fit in the gaps we wanted to block. The gates come with a template to cut out & fix to the wall to aid alignment of the hinges & catches. Nice idea. I only used the template for the hinge side and then aligned the catches by eye, but the whole process from opening the box to having the gate fitted took me 15-20 minutes and I was in no rush. You'll need to check whether the wall is suitable for drilling & supporting the weight of the gate. In my case it was wooden door frames so the included woodscrews were sufficient.
You then need to adjust the bolts connecting the hinges & catches to get a good fit that allows the gate to swing naturally and clip into the catch each time. This takes a bit of fiddling around but isn't difficult.
The gates have been fitted for nearly a month now and we find them easy to open & close one-handed but our 18 month old is safely contained. She tends to climb onto the bars and the fixtures have taken her weight without problem. They look tidy & are much easier to use than some of the quick fix gates we've seen. As they open completely, there's no risk of tripping over them when you go through either.
We only have two minor complaints. First is design - the clasp that allows you to adjust the gate width is in an oval shape that sticks out beyond the width of the gate itself meaning that with the gate engaged we can't close the door. Not really a problem but it means that if we close the door the gate is left to swing on the outside. The second is that one box was missing some crucial bolts. To their great credit, a quick phone call to Lindam with a description of the problem saw an envelope containing the missing bolts arrive in my hand two or three days later. This is the second minor quality control issue we've had with Lindam (we also own their lightweight play pen and the structural screws on that product were all loose & needed tightening to render the play pen safe to use). I believe their designs & customer services are very good and would recommend the products we own but would warn users to check them carefully before relying on them to protect their babies.