I've a can of this which I've had for about thirty years now and I'll use it, umm, very infrequently. It IS a superb product though.
For day to day working I just use hairspray, my current being:VO5 Hair Spray - Extra Body Hard to Hold 14 Hour Hold 250 ml (Pack of 2)
which I just reviewed AS a fixative. If anyone has come across a better alternative I'd be delighted to learn of it.
The Winsor & Newton is a little better for "gallery" quality work, though of course never quite as good as no fixative at all; it does tend to flatten the character out of a rich pencil drawing and (I don't use them myself) it turns pastels and chalks into crayons and kills a lot of the "freshness" BUT it's a darn sight better than having a work ruined by smudging so if it's not going under glass _immediately_ but might, someday, then the W&N is good insurance. It's very clear, non-yellowing in my experience (whereas paper usually isn't) and tends to wrinkle far less than the cheap substitute.
Of course I'm just a hack illustrator whose drawings are usually just a stage in producing something in a different medium so fixing with hairspray is a sensible alternative. Your mileage etc. etc.
First class product. If it's essential (difficult choice) I doubt one would find anything better. Expensive