I'm around 6 years or so before my big 50 and I certainly see myself wearing sleek lasts 10+ years from now. I say if you like it and suits your style, go for it!
As for the chukka above, I think the Milton needs a dressier outfit. If you normally wear casual, the Hartland seems like it may be easier to wear.
All the best!
I agree with your comment about the C&J Milton's needing a dressier outfit. So, I will reserve them for smart casual / dress use and purchase a pair of C&J Hartland and/or Tetbury suede boots for casual / smart casual use.
Thanks for your words of encouragement!