I honestly can't tell you anything about the strider. never seen one.
I can tell you that our infinity has done us proud until now, with a few issues. DS is 2 and a half, and is looking a bit big for it, but should still be fine for a while.
It is really easy to push, and fine on bumpy terrain - although I havent taken it over anything bumpier than a farmers field! I think it would be fine, its quite robust.
No you can't reverse the wheels - the smaller ones are always at the front. You can only reverse the direction of the seat.
The issue I had - which may be relevant as the winter is on its way, is that the waist strap is not big enough when the child is wearing bulky clothes. (This may have changed - we bought ours in 2006) Even when DS was a baby if he wore a snowsuit it was a bit tight on him. Its not so bad now as he doesnt wear all-in-ones so can have his coat over the belt. But it is a bit silly.
Also it has a good recline, but wasnt 'upright' enough for him at top position. A cushion of course can remedy this.
The basket is ok, not really big enough for anything other than a raincover and a few other items.
But the seat is nice and roomy, and ours has the rubber footrest which is great.
Am trying to thing of anything else that may be useful...
oh - the footmuff was great (although he's too long for it now - actually he's too long for most footmuffs now). I like the way it zips either side - and theres plenty of room in there and it comes high enough to cover.