Zymol HD Cleanse

Is this the best 'paint prep' available or are there other products which will do just as good a job?

I saw demo of it being used once and was V impressed by the lack of effort required ( after claying) to achieve what looked like a perfectly prepared surface , ready for the next stage of waxing etc.

I'd like to get some, but at fourty quid ( for the larger size), I'd rather try summat else!

Any suggestions welcome. I would be applying it by hand, btw, not that cult P.C machine!

Tia