Help me choose a new waxless backcountry ski

Pardon my ignorance, but could someone explain the whole "not enough boot" concept. I come from a cross country background, and get some of it. Obviously, you can't put a regular cross country boot on a heavy metal edged ski and expect to make good turns with it. The boot is too floppy, and the ski is too heavy.

But with these skis, they look to be about the same weight. More to the point, it looks like the Vector BC is lighter than the Rossignol 125. If so, then why could you drive a BC 125, but not a Vector BC with the same boot. What am I missing?

(thanks in advance)

Good point and fair question.  It should have occurred to me that my statement was not defensible based on ski specs.  I own both of those skis (also most of the others discussed here, including the X Terrain, which I've championed here in the past - but the Rossi is a far better meadowskipper when trolling for turns).  I skiied most of last year on the BC125, both bc and resort and I've loaned them out both last season and this one, and we all agree, the ski handles like a Miata.  I've skiied all of this season on the Vector - it's not a Miata.  And the Vector feels much better at speed than the Rossi even with a very similar running surface length.  The Vector BC came from the alpine side, built with carbon, to which they added a pattern base - the Rossi comes, seemingly, from the nordic side, scaled-up and shaped for the down, including on-piste.  Comments from ski engineers would be welcome here..

But what does this have to do with the boot, T4 or otherwise?  Simply that the Vector skis like a larger ski - still fairly nimble, but more stable, and rewarded when given bootcuff pressure and rolled ankles.  Sure, you can 'ski' the Vector with a T4, but you won't find the skis' potential with such a touring shoe, IMO.

I'm holding firm with my vote as noted earlier, in this application, for the larger S-Bound unless the OP wants to change out other gear or to bias more toward turns in which case I happily recommend the BC125  (or 123   )

Thanks for the explanation Steve and David. I now understand the general principals, and they make a lot more sense to me. I appreciate the details, too, about the specific skis. This is definitely information that is hard to gather by just looking at the ski or reading the description.

... As I mentioned in my prior post, the Guide/Annum I tried was very soft, a real wet noodle. ...

Big Steve, I'm wondering what length Guide you skied.  I'm 230 lbs and I ski the 195 cm and wouldn't describe it as a wet noodle compared with my  Fishcher Outtabounds, Salomon X-Adv 88 (supposed to be the Rebound, but my 190s have the strongest double camber of any waxless I've skied, and the poorest metal edge), Karhu Catamounts (a weird flex) , or Black Diamond Valmontes (soft, single camber, altho advertised as 1.5 camber)--I get better kick-and-glide (exc. for the X-Adv), climbing, and turning with the Guide (because of my weight, I almost always use the longest ski in the model; on true XC skis, I use the paper under the foot test to choose lenght).  They are noodly compared with my Madshus Voss (which I used for groomed trails and some off piste on the Methow trail system). I've used them on fairly high speed downhill runs on the MTTA (roughly and occasionally groomed logging roads) and they hold an edge well and turn surely but I found them not to turn that well in deeper backcountry snows (length + flex?)--especially compared to my real bc skis (Volkl Snowwolf and Dynafit 7 Summits and Manaslus).

True - I'm more of a tourer, but I want to be able to tackle the hills.   

I'm not that skilled making turns on my Fischers.  If it helps at all, here's a link to pictures from my last trip to a lookout.  They might give a better idea of a typical trip.
picasaweb.google.com/1184265963414814989.../5711967821843438722

Looking at what your doing. Volie Vector BC. Final answer.

Any suggestions on where to buy?  I live in Salem Oregon so I was thinking Bergs Ski Shop in Eugene, Oregon Mountain Community in Portland, or Mountain Shop in Portland.  I guess I could wait until my next trip to Bend also.  I'm at 200lbs plus more with a pack so I'd need the longest length I'd expect.

I hear REI has a great return policy.  Will they order skis they don't typically carry?

Thank again for all the advice.  I'm still undecided! I'm thinking with the T4 boots it might be best to go with the Rossignol 110's or the Fischer 112's. If my boots and Voile bindings could drive the Vectors, those look pretty sweet.

I'm not a big fan of REI (I am a member); I've purchased skis from OMC in Portland, PineMountainSports in Bend, AlpineExperience in Olympia, MountainGear in Spokane, Marmot in Bellevue, Backcountry.com (& outlet), Bentgate.com, Telemarkpyrenees.com ...  all provided good service and decent prices; I like to support local shops vs. chains/internet only and will pay a premium to do so to have service and advice available locally; but sometimes I have to go on line to get exactly what I want or something less than MSRP.

I've also purchased gear at the TAY sponsor, ProGuideService, they have a winter sale on now; but I don't recall seeing any waxless skis in there the last time I was in the shop.