I have owned two pr of the old Gotamas and skied the 2010 186 about 5-6 different occasions last year. I have also skied the Czar a fair bit as well over the last two years. While the Czar is a tip rise only ski, the rise is more pronounced than the front portion of the Gotama. The remainder of the Czar is conventional from the contact point back. The Gotama OTH, is a continuous rocker albeit fairly moderate in amplitude.
You don't say how you want to use them but there are two likely scenarios (powder only or everyday)
Both skis are on the narrow side for a powder specialty ski but if that's what you want it for, they both ski deep snow well considering their widths. While they are different, IMO there is no dramatic advantage either way for deep snow. For that context, I'd be happy with either one.
If you want more of a big mountain character, (meaning a bigger ski with utility in other than powder situations) that is a somewhat different kettle of fish.
On consolidated surfaces, the conventional section of the Czar is reasonably solid. It is however, wider and softer and you will notice that the soft, rockered tip feels disconnected. In those conditions, the Gotama feels loose and sort of "vague" for the whole length because there is no conventional section to stand on. If you can build enough edge angle to get the sidecut connected to the snow, the Gotama settles down at least somewhat.
The area where there is a notable difference is a "mixed salad" day. This is when you might have 6"-12" of skied out 2 day old snow over a firm surface. In those conditions, you'll have patches of firm stuff where the snow is scraped off, clumps of fairly soft chop, and quite a bit of crud that is consolidating toward incipient bumpazz. Neither ski is particularly good at this but for my personal tastes, the Gotama can't decide where to go or what to do. At least the the conventional section of the Czar is a more stable platform in these conditions.
So.....both skis are adequate narrow powder skis but neither particularly excells as an everday choice. If I had to choose one of the two for powder use, I wouldn't particularly care. If I had to have one of those two with some everyday conditions in mind, it would be the Czar.