Hi All, Coupld of quick questions for you pro's Would 10mm underlay need taller grippers or can they just be doubled up? I am debating on the following carpets: First Impression Heartlands Heartlands Heathers Heartlands Ultra What is one of the better carpets above, would it be the heartlands ultra? I'm looking for something that's quite a tight pile and wont flatten too quickly. Secondly, I need to chose a underlay, something that i can have all around the house and stairs and is dense and will protect from flattening but still feels quite nice underfoot. My options are 9mm caviar and crystal Or a 10mm connoisseur or super contract by cloud 9 (would this be ok on stairs and would I need thicker grippers, standard or can I double up existing ones) Also, have you had any experience with something like a 11mm memory foam underlay. Not seen much about memory foam. Is it dense?