The old Elu machine they used to make is excellent with really good filtrtaion and low noise level.
The new/ current range in my opinion is a case of high price becauese of the brand, The machines are really pretty basic, very noisey and far too expensive for what they offer.
I cant comment on the level of filtration but I would be surprised if its anything but average.
I would suggest better value and performance with Bosch, trend or some of the other well known brands.
I would also urge you to think seriously about getting a machine with a low db rating, I promise you will be glad you did so.
beejay