A B737-700 FLT CREW ON ARR TO SNA EXCEEDED THE 200 KT SPD LIMIT BELOW THE CLASS B FLOOR.

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DURING A VECTORED APCH FOR RWY 19R SNA; ATC ASKED OUR AIRSPD. I SAID '230 KTS.' HE RESPONDED; 'YOU'VE GOT TO BE KIDDING ME.' I DON'T KNOW IF HE MEANT IT AS A JOKE (IE; RADAR INDICATED A MUCH DIFFERENT AIRSPD) OR IF HE WAS IMPLYING THAT WE EXCEEDED THE AIRSPD RESTR BELOW CLASS B AIRSPACE. NOTHING ELSE WAS SAID CONCERNING THE AIRSPD. WE SLOWED TO 200 KTS AND CONTINUED THE APCH. REQUIRE ATC TO KEEP ACFT IN CLASS B AIRSPACE DURING VECTORS. POSSIBLY ENHANCE EFIS MAP TO SHOW AIRSPACE RESTRS. I KNOW THESE TWO ARE NOT PRACTICAL. THIS WAS MY FIRST APCH INTO SNA IN PROBABLY 2 YRS. THE CHART INDICATES TO USE CAUTION IF YOU GET AN EARLY TURN ONTO A DOWNWIND LEG. I WASN'T FAMILIAR ENOUGH WITH THE APCH TO KNOW WHERE AN EARLY TURN MIGHT OCCUR AND IT WAS OVCST; SO WE HAD NO VISUAL CUES. NEXT APCH INTO SNA; I WILL SLOW TO 200 KTS EARLIER THAN I HAVE IN THE PAST. I THINK IT'S BETTER TO BE LOOKING OUTSIDE FOR TFC RATHER THAN BEING HEADS DOWN REFING CHARTS AND VORS IN ORDER TO FIGURE OUT WHEN YOU MIGHT BE BELOW CLASS B AIRSPACE.