I drew up this table so that I can see what items to get to get the most out of set equipment.
edit: note that the Bounty Hunter set appears to be 15% Boss only.
I've also included one of the recent KMS 1.2.218 sets, the Boss Accessory set, for the sake of complete comparison. It appears that the full Fafnir set + 3-piece Sweetwater set might be able to match the full Sweetwater set, because 75 ALL and 2 WA can be roughly made up by a fully scrolled and potted and nebbed bottom...
With Superior Gollux around, there's not much room to play except for the Meister set and the Boss Accessory set. As of now, it does appear that the Sweetwater accessories are the best due to them being Tier 4 potential and having enough slots to scroll and PChaos them. The Boss Accessories (they're all Tier 3) to aim for would be Condensed Power Face Accessory (5 ALL 5 WA, 5 slots, equip tradeblock), Black Bean Mark (Eye accessory, 7 ALL 1 WA, 5 slots, untradeable) and Silver Blossom Ring (5 ALL 2 WA, 2 slots). Optionally get Royal Black Metal Shoulder (10 ALL 6 WA, 1 slot) and Pink Light Grail (Pocket, 5 ALL 5 WA).
Would you all bother with the new accessories for the upcoming set (assuming it comes to GMS)?