I think you know the answer. Deep down, what do want people to say? "Go for it", or "keep your SLC"?
I bought a 10x42 NL, and while it's an optically brilliant bino, the novelty has already worn off (it's been about 3 weeks). I think it's easy to fall into the trap of thinking that an object will dramatically alter your quality of life, or that minute optical improvements will change the way you go about your birding/hunting/nature watching - whatever.
The NL's are good tools. But they're not magical 'wonder' instruments, either. If you've got the $$ and you feel that the extra features of the NL may contribute to your enjoyment, why not? But I don't think you'd be missing out on much by sticking with your SLC's.
At the end of the day, it's what you view through your binos that counts, isn't it? This forum has been a bit of a negative influence, because instead of enjoying whatever it is I'm looking at, I've been preoccupied with nitpicking the glass instead. And even the NL isn't immune to that. I've been picking holes in it all day long, and it sucks big time.
The grass is always greener. If you think the NL will cure that, then you're wrong.
If you find the SLC to be fantastic, then why change? If your answer to that is "but...." (etc) - then buy the NL's. :0)
I think that this comment just about nails it. If you have the money and a superbly ergonomic pair of bins with an exceptional FoV and edge-to-edge sharpness are very important to you then give them serious consideration. However, except in direct comparison, the improvement in the quality of the image is such a subtle incremental change that you won't notice it in normal field conditions. Existing high-end Swarovski binoculars are such good instruments that it would be fanciful to expect a really significant improvement in the image. For a similar price, you could have a pair of Swarovski EL 10x42 and CL Companion 8x30's which would arguably give you better flexibility. That's the logical argument but - courtesy of a healthy rebate from my energy supplier - I surprised myself and got the 10x42 NLs. When I've recovered from the financial shock I'll almost certainly get the forehead rest which was surprisingly effective so much so that it's surprising they're not 'standard issue' for all bins.