Think Twice
Here's my story - for what it's worth to you as I think there are some parts relevant to you and maybe you can compare. I'm 30 and my dad is currently 67.
I grew up with my dad Buying Mtn. Max rides. They were great at the time. When 07 came around, My dad was on his 2001 MM700 (144), so was my brother. My dad had a 99 MM700 that I could have ridden, but I chose to go buy myself a 2008 M8 (153).
I loved that sled!!!!!!!
One day I got back on my dad's MM700 and let him try my M8. I was obviously really glad I wasn't riding his MM700 anymore, and actually, he didn't really care too much for my M8 - he was pretty happy to hop back on his MM. I couldn't figure it out. I loved that M8 soooo much, how could he not feel the same? Maybe he just wasn't used to it?
2009 I sell my M8 ($$$$) and I'm back to riding his machines. Fortunately, also in 2009, he buys a new stock Nytro 153. So at this point I'm riding the 2001 MM instead of the 99, which is nice for the longer track mostly, and he's on his Nytro. He felt bad that I had been demoted from my M8 back to his MM, so he would try to get me to be the jerk and steal his brand new Nytro from him so that at least my demotion wouldn't be as far of a fall. I refused as I kept thinking back to him not liking my M8 and the only thing that I could come up with was that he really needed to get used to riding the new (rider forward) style of sleds.
Then probably about February of 2011 after he had been riding the Nytro for a year and a half, on a fluke, we switched back for a minute. The next time we went riding he demanded that he get his MM back and not for my sake but his. He said he just had more fun on his MM because he just didn't have to work so hard to ride it. He has never looked back. Every time we go I make sure he has the choice of which one he really wants to ride and he always picks the MM. I don't mind, because I'm younger, so I still have the strength and stamina to fight with the Nytro and still have a fun day, and I like the extra power it has over the MM. It isn't like my old M8, but it's certainly closer to it than the MM, so it works. Except that my Dad bought a brand new sled and is still riding his decade old sled. Not cool, so I'm on a hunt for a new sled that he can buy that he will like as much as or more than his MM.
So in January of this year, we go to the Polaris Demo. By now I'm suspecting that the track length might have a lot to do with why he didn't like my M8 or the Nytro (both 153), so when we demo the Poo's, I make sure he gets a 600 144 and I go an hop on a 800 155. Riding for a while, he really likes the Pro 600, so I say ok, let's switch. Now I hop on the 600 144 and he is on the 800 155. He doesn't like it a bit. I tell him keep trying a little longer and then when I watch him and realize he's not having fun, I go give him his 600 144 back and he's right back to having a good time. Realistically, if we could find a 600 144 for him at a decent price, I think he would buy it right now and sell the Nytro.
For right now, I still have fun on the Nytro. The feel is kind of like my M that I loved. It just has less power and more weight to fight with and isn't quite as stable on the sidehills. It kind of wants to either get all the way on it's side or sit straight up, it doesn't as much like to sit right in that in-between position as easy as my M did, or really even as easy as the MM does. A turbo would cover up a lot of Nytro sins - for me. But I don't think a turbo would have made my dad like it any more than he already did. He just doesn't have the strength for the weight, and he just doesn't have the strength for the longer tracks. He did 7 years ago at 60, but for him (and I understand everybody ages different so this may not be the case for you) his 60's have been pretty brutal to his body strength
Anyway, really long story for the final summary: If you're anything like my dad, you might find yourself caring a lot more in the next few years about lightweight and easy to handle than you do about how much power it produces. If that's the case, you certainly won't like a stock Nytro, and I really don't think a turbo would make you like it a ton more.