I always wondered why my Japanese friends taught me the form "X-san oshiri wa suteki desu" rather than "X-san wa oshiriga īdesu" which is what Google Translate suggests for the English version of the sentence in its most natural form.
"X has a good butt" doesn't sound terribly natural in English either. Also, X ga ii has a connotation of preferring X over other alternatives: X ka Y ka docchi ga ii? X ga ii.
