Part of the issue depends on how important you feel that it is for your wing to float at the surface if you ditch it. In some configurations (minimal weightbelt, ACB pockets with total of 20 lbs, stainless steel backplate and weighted STA) a 30 lb wing won't have enough buoyancy. The same wing however should easily provide enough lift for a single tank. Where it begins to become gray is when you're dealing with a thick wetsuit at depth. If you were planning on only diving a drysuit (which should have a lot less buoyancy swing) a 30lb Eclipse is a great choice, with the 40 being only slightly worse. I've had a 40lb wing in Cozumel with my 3mm wetsuit and I still had far better control than those on rental jackets and I sure as hell didn't feel much 'drag'. Anyway I'm done on this topic. I have a LOT of wings and to be honest I can't tell them apart. I did like the Halcyon Cinch system which is why I suggested it. Good luck.
I'm still confused about the 30lbs vs 40 lbs, and the dozen of PM I've received to help clarify the situation have ended confusing me more. I don't understand how so many people can feel so passionately AGAINST the 40lbs and for the 30lbs, while others feel the almost extreme opposite. Either people are convinced I will NEVER need 40 lbs and it is completely overkill and others say it'll be fine and will come in handy for the future.
The dive shop offered to order the 30lbs for me specifically so I doubt it's about keeping inventory to a minimum, since they'd be ordering it for me and ship it out immediately. But, for argument's sake, say they ARE biased for whatever reason, this still leaves the debate at 50/50 between people arguing this issue. I am too inexperienced to really grasp the nuances of what 30lbs vs 40lbs means, and you all appear convinced and passionate whenever you present arguments for or against it.
If wings were cheap I'd buy both, but at 400$ a pop or so, no way.
