The heaviest loads I've had on it before were a '74 2wd Crew cab with a 454; an '83 1-ton 4x4 Dually regular cab with a 454; and an '84 regular cab with a 454 and 1-ton axles/winch and 38's.
That Dually actually seemed heavier still than this latest SRW Crew Cab... even though the Crew Cab has a big block too... but a few less pounds since the 60 is gone and a 10-bolt resides up front. (a 3.73 10-bolt front by the way, with a 4.10 rear... people are morons).
My trailer, despite its looks and the fact that it used to be a travel trailer from the '60's, tows excellent. It has never once fishtailed. The only thing you ever notice when towing it is the extra weight. Even when I towed it... a 22' bed trailer (25' overall), with my '84 K5 in the past, it handled excellent.