The only time I go with the wave is if I have something mechanical that I'm bringing (something motorized, etc.) and I need a mini tool kit. There is nothing in the woods (or in a 'bushcraft' sense) that the SAK can't do better than the wave.
Ditto on hauling a Wave when you have mechanical stuff. The SAK is lighter and less expensive too. If you own a Wave, it's better than nothing by a long sight. If I found myself in a tight spot and only had a Wave, I would be counting my blessings and not crying about it

I think a good multi-tool is the ultimate Urban Survival Tool (we coin UST?) and I EDC one.
Consider what tools you need in the woods. I've gone searching for the Perfect Multi-tool and it usually comes down to something like scissors or a saw when looking at one model vs. another. An SAK Classic can fill the scissors niche, as well as toothpick or tweezers, or you can get a small pair of scissors that work better than any knife-bound ones that weigh 0.5oz. Fiskars makes some good small ones-- You can get them uber cheap on eBay. A Gerber Sportsman's saw will provide a better saw than any multi-tool for $12 and only 3oz weight.
You can buy a decent folding knife, scissors and folding saw for the same or less than a good multi-tool and end up with similar weights too. By having separate tools you spread out the risk of loss or breakage (at the expense of simplicity and space).
If you go with a Mora, a small pair of scissors and a Gerber Sportsman's folding saw and you have 7oz total weight and about $25 invested--- less than Ebay prices for a middle-of-the-road SAK, and you have a very usable fixed blade knife, good scissors and a saw with a 6.3" blade. Weird, huh? These aren't the toughest tools, but IMHO they are at least as tough as multi-tool blades.
The issues are really compactness and fashion. I'm prone to it as much as anyone-- my Mora just isn't isn't as sexy as a nice Leatherman or even an SAK. But when you get down to saving your backside, the Mora and the larger saw looks better to me. I own all the above too!
I forgot to add a p-38 can opener to the mora/scissors/saw option :thumbup: