Problem..

Lab 0001 -> 161-131-161

So at first glance I would say Lab 001, however when one considers the fact that the Opus is a 192 and the Lab 001 is a 181, perhaps the Opus is the more floaty. If I've understood what you've said correctly, the only accurate way to say which is more floaty is to look at the surface area of the skis. They aren't provdied on either of the companies websites. However I'm sure some guys on here will have them to hand, and sometimes Surface and Line check the forums for any questions about their gear which unanswered questions about the gear, and they'll be able to tell you.

Although, if you're set on the Opuses, get the Opuses and give the Surface pro-form to me. ;)

Hence the best way to look at how floaty a ski is, is to look at the surface area of the ski. Whilst some companies provide surface area specs, such as Armada, neither line nor surface do.