I've seen too many 525s struggle with decent fish on, on the other hand Slosh30's are like lifting machines comparatively (can't comment on 535s with bigish fish on), My Abu 7000 has never let me down it has mint pulling power their only let down being the drag is rubbish so needs clamping down real tight and the retrieve speed is too low but then that's probably what gives it that winching power.
Also agree with 'The Great Wallsendo' the Okuma MG30, I've seen my MG20 (the substantially smaller one) lift half a tree up the side of Roker Pier! I have every faith they are good lifting machines, but the MG30 really is a big reel.