Once you get going with the sanding, you'll soon get into a rhythm.
Geraldthehamster - your point (ChilliBob, this is off-topic from your thread so perhaps I should be putting it in a seperate thread!) about water-based varnish (or lacquers as they are termed in the trade) being inferior to solvent-based equivalents is a common misconception. Back in the 80s I would have agreed with you, but the rate of development in chemical engineering has resulted in many water based lacquers far surpassing the durability of the solvent-based products they replaced. Remember that water or solvents are in the main just the vehicle to get the product in the formulation from the container to the surface being coated. Both evaporate to leave the coating product. Each has pros and cons (water evaporates faster than solvents so you can finish the job faster, solvents react with wood turning the fibres yellow/orange, water doesn't, water raises the grain, solvents don't etc etc.
I haven't tried the Ronseal product you link to but professional manufacturers like Bona or Pallman have a range of floor lacquers to suit environments from domestic bedrooms to shops to restaurants to hotel lobbies. They are in an entirely different league to Ronseal which is essentially a consumer DIY product. The word lacquer also conjures up images of high-gloss finishes but this is misleading - the sheen levels range from almost invisible dead flat to matt to satin to gloss to piano gloss with countless sheens in-between. And this is the point about number of coats - the chemical engineering is now so precise that applying more coats than is recommended, apart from looking shoddy, takes you over the peak performance curve. In that too much product build-up and it starts to chip and scratch more easily.