Rossi B4?

This is a questions to you guys who tested many skis this year:
I have a chance to purchase this year's Rossi B4 at a very good price (more than 50% off) and I am wondering if I should jump on the opportunity. I am a 6ft, 180lb male, I ski at Tahoe, expert skier. I am not overly aggressive: although I ski at fairly high speed I always favored technique and finesse over raw power and speed.
I feel very comfortable with both traditional and modern technique, and given the choice I'd ski on ungroomed steeps, bowls and/or bumps all day. More to the point: my current (and my favorite) ski is the Dynastar Legend 8000. I really like its quickness, good hold and great bump skills (it is amazingly good in bumps for a midfat). I used in quite a number of powder days this season and although it has been very nice I was always wishing for a true powder ski. So, the B4 is intended to supplement my 8k's as a second ski for powder/crud/soft mush days.
I did have a chance to demo the B4's a week ago at Tahoe. It was wet powder in the morning which turned into a half frozen crud after lunch. The B4's felt much less turnier than my Legends, but much more stable. It felt amazingly quick and stable on steeps, and nice and smooth in the chopped up stuff and I was generally having a blast all morning. Afternoon was worse, the B4s didn't really like the frozen chopped-up stuff that much. it was better than my Legends, but I didn't have a feeling that I was just bulldozing through the crud (maybe my legs were getting tired by that time). I did take it through some moguls and was surprised how well they did it for such a wide ski. I was also able to make it "dance" but it was not nearly as effortless as my Legends. I also demoed a pair of Pocket Rockets and they were fun, but I prefer the B4's, as the PR tails felt way too soft for me.

My questions are:

1. Is the B4 a mediocre example of a fat ski, or this feeling of slight sluggishness a consequence of the ski's wide girth and moderate sidecut (as I suspect).

2. Should I jump on the chance and get the B4's or is there something new coming out the next season that will make me regret the B4's? I did see the new BSquads and they are WAY too stiff for me, as I don't generally like to bomb down the mountain at 50mph.

3. Is the B4 a good second ski for someone who loves how Legend 8K skis? FWIIW, I always liked Frenck skis, I never demoed an Austrian/German ski that I liked, they always wanted to do their own thing, and French skis felt very cooperative. I will be weary of getting a stiff ski that would plow through the crud, but would not do anything else to my liking.

Thanks in advance for your advice.

Thanks for the opinion. I do agree with your accessment. I am not sure I even care for how they feel on groomers, I already have the Legend 8000 for that task and I am prtty sure that they are more suited for groomers than 8800 or B4's. In retrospect I regret not buying 8800 instead of 8K's, as they may have been a one-ski does it all solution for Tahoe. I am looking at 185's in B4, as this is what the shop (and Rossignol tech support afterwards) recommended for me (however, my 8K's are 178, which was the shorter of the two sizes that I liked, and I definitely would not go any shorter). So it looks like B4's indeed may work well as an addition to my Legend 8K's, but I should keep them for the days when it is dumping...