I just got an Ice Spiker for my sister in law's old Raleigh.
Conditions today were a variation between mostly dry pavement with ice patches on the MUP, and everything from deep (4-5 inches) powder, packed snow, pavement, rough ice, single track ice/packed snow through parks, rutted ice on roadways, and icy footprints.
The ice spiker did really well (my experience is with a haaka 106/marathon snow stud/innova), with the only problems on the powder snow. Single track was tricky because if I wandered too far, I would drop down off the packed stuff onto powder, which usually meant an abrupt stop.
Icy ruts were no problem at all, and while I did not corner at speed at any time, there was no slippage on glare ice or any of the other surfaces that I tried.
That being said, the best part of the ride was getting back along the Bow River, taking in the scenery and enjoying the 'crunch' sound of snow being packed under me.
My only question is this - where is everybody??? I couldn't imagine a nicer day for riding, and I saw like 4 riders tops. Come on out, kids - you won't regret it