I'll throw in my .02 here

I needed seating for 6, but still wanted good performance. I went with a Ranger 800XP with a Supercharger.
Even though it will never handle, or rock crawl, like a RZR S or RZR 4, it will out accelerate (and high mark in the dunes) either one of them every time, even fully loaded.
My particular machine was an exercise in dumping ridiculous amounts of cash into a machine, that I will never repeat. Truth be told, if I had it to do again, I would get the Ranger crew with power steering and save myself a TON of cash. The crew would rock crawl much better than the XP as well!
I have figured out that with a Ranger crew 800 as the base vehicle, the same kind of overall performance can be had, for a fraction of the price.

If your family only has 2 kids, I think the RZR 4 is the ideal machine! However, with 3 or more possible kids, you may need to think about not only how you can squeeze them in to a machine right now, but what situation you will be in when they grow a little bit. If they are all squished into a machine that can't adequately handle 5 people, you may find that compromising a little bit of overall performance will be well worth the extra enjoyment for your kids.

BTW, with the extra power & reprogrammed ECU Brutus can go 61 MPH (GPS). Not far off what a RZR 4, or RZR S can do.

Knowing the things you can do in a RHINO, I am absolutely terrified to think of what you will be doing in an XP!!!!

I’m guessing next time we see you take the Escalator, you will hit the first bump, and land on top of the hill!

Very nice!
Looks like you had the place all to yourself.

I am very impressed!
Not only a significantly more powerful motor, but reengineering the drive train to minimize horsepower losses is a very good move.
I suspect that all things being equal, you would have to make a little over 100 horsepower with a RZR S to have the same power to the wheels as this new machine at 88 horsepower. It's all about efficiency, and getting the power to the wheels.

On the one hand, I can see the extra 4.5 inches of wheelbase being a big improvement to the stability when rock crawling. (Similar to a RZR 4, but without the turning radius drawbacks of the RZR 4 in the tight spots)
On the other, I can see the trailing arms dragging over some of the more extreme obstacles.
I'm sure someone is going to make some UHMW protectors for those arms, and It shouldn't be an issue.

I am excited to see these things in action, I'm sure they are going to be very impressive.

My current needs more lean toward a RZR-4, and I am disappointed that they didn't make a RZR 4 XP. 
I also don't foresee them doing that very soon (If ever)
Looks like I am going to be in the market for a RZR 4, and will be talking to Aerocharger to give it the power I will need it to have.

Props to Polaris! They own the sport SXS market! 

"800 pounds of human"

Now that is just damn funny!

I don't blame ya at all. The word Stealthy doesn't apply to any part of Brutus though... It's about as stealthy as a sledge hammer to the groin.

Yeah, there were plenty of bugs to work out.
That's the problem with prototypes.

The other problem is that to my knowledge, nobody has a "Production" kit of any kind for the Ranger XP 800. (Not even the Aerocharger OR MCX kits that were made for Project X are in production.) (Not enough people are willing to pony up the dough I guess.)

I am extremely pleased with Brutus now, but if I had it to do again, I would have left the engine normally aspirated. Then I would have bought a RZR 4 and installed an Aerocharger Turbo that has already been proven on the application, and is in mass production.

You're being a little tough on old Polaris aren't you?
I vaguely recall a certain Rhino that left us all in the lurch...

Even with almost double stock horsepower, my RZR has been extremely reliable over the entire 4,000 miles I have owned it. I think Polaris already has a solid machine, even for those of us who add more power!
With few exceptions, I think they got it right in stock form. Even my plastic Sprag was in perfect condition after 4,000 miles. (Although using plastic on a part for that purpose is a little cheap)

Look at it this way, the terrain we have here is some of the most challenging in the world. The vast majority of SxSs will never see the kind of abuse we can easily dish out in an afternoon in Moab. Even the Can-Am (A very well engineered machine in my opinion) broke the steering rack on its first trip down there!
When we take our machines out and climb vertical walls, we are bound to break parts.

No company is going to be able to build a machine that will handle absolutely everything we can dish out, especially for $10 to $15K
These things are built for the masses. If you or I decide that Rock Crawling or full throttle jump landings are our thing, we have the aftermarket to help with the weak links that we will inevitably find.