The problem is that few modern ropes can be spliced with oldfashioned techniques - but they can still be spliced.
The manrope knot can be tied in Amsteel, because it's 12-strand, but you can't do it in double braid.
So, for working splices I prefer up-to-date instructions. The book (or online PDFs) by Samson ropes are my favorites (I use the book, because I want to work away from the screen). They are well written, easy to follow, and seem to come out without fail.
Some splices in modern ropes feel like magic. At first, it seems impossible to understand why a particular series of steps is recommended, but if you don't lose faith but follow through with marking, tapering, pulling through and smoothing out, suddenly you have a perfect splice in front of you.
For winter reading, nothing beats the more traditional books. Of Smith's books, one reviewer wrote: "they feel pleasantly ancient in 1950s sort of way". Then there's Ashley's Book of Knots - now that's something you can get lost in.
I like to keep an eye out for modern knot books as well because some old standbys don't work well with slippery modern ropes and also because there have been a few innovation in other fields, notably climbing, that are just worth knowing about.