“Comparisons are odious.” ~ 14th Century Saying … and odious generally means hate inducing. Coupland and Ellis are two of my favourite authors whom I have deep deep respect for. I would look at Coupland’s first novel, Generation X, and relate it to Ellis’ first novel, Less Than Zero then look at Generation A or Player One: What Is to Become of Us (or Generation A) and Imperial Bedrooms.
So to answer / not answer your question, yes they are on a different plain and yes you can compare them.
Personally I think Imperial Bedrooms is one of Ellis’ strongest novels (and I’ve read all of Coupland and Ellis’ canon).