Pssssst... replace them all with stainless steel hex-drive button head screws. Bring it into the 20th century, now that we're in the 21st.
mnem
*agitating-ily*
Since you're living in Canada, you mean stainless steel Robertson screws, right?
Absolutely not!
I find them viscerally offensive... like square-headed bolts and nuts. They are just plain butt-ugleee!
At least the US has settled on Philips as their LCD fastener type (but is fast taking up Torx as the "upgrade" or most common "better" type over Allen/Hex-drive)... it's like Canada totally devolved with slotted and Robertson as pretty much the only fastener types aside from hex-head bolts.
mnem
*blerk and a half*
That is how Canadians show their patriotism. Robertson was the Canadian inventor that patented it. Not sure if he actually was the first to come up with this...
I have no issue with good quality Robertson screws and drivers. They work great; very common for outdoor structures like decks and stairs.
However, poor quality Robertson stuff is absolutely frustrating, which I have only found in the last few years.
The latest batch of drivers I bought are pure crap and are horrid to work with; these came from a so-called quality brand.
Luckily, I found some old drivers in Grandma's barn ... they work great; keeping them for screws where I might need to re-use.
Recently, Robertson screws have been coming with anodizing/coating/paint over-applied and filling the head. This makes it hard to properly fit the driver, or if it does fit, makes it difficult to drive straight.