I own it and have used it for about a year.  In general, I think it's a very well written and well organized book.  But my results... more draws than i ever thought possible in the U1800 section!

His lines seem best suited to older (patient) players who aren't necessarilly striving to get an advantage out of the opening, but reach a respectable position with more strategic depth than other "safe" options such as the London or Torre attack.  Although a 2400 IM with excellent end game technique might play these lines "for the win", they may not be the best choices for the average 1800.

The real bane of the repertoire for you will be the Slav.  The Slav is immensely popular here in the US at the 1600 - 1800 level.  Unfortunately, his attempts to avoid the main line semi-slav at all costs lead to very tame white lines.   

If you are young and/or ambitious, you might find more agressive lines will bring you better results.  Since i'm old (bad memory) but not terribly patient either, I have opted for slightly more agressive lines than Palliser recommends vs. the slav, QGD and fianchetto defenses.  But I like his ideas vs. the QID, Modern, Chigorin, QGA and minor sidelines. 

I found Grivas' book "Beating the Fianchetto Defenses" to be a great way to spice things up a bit while still staying within the realm of Palliser's positionally sound d4/c4/Nf3 approach.  There is some overlap in their treatment of Grunfeld, Modern and KID sidelines.  But Grivas' benoni and benko lines are more consistent with a repertoire theme of space advantage and selective agression.  

You might also have issues with the multiple dutch systems required in Palliser's repertoire.  A simpler approach (from a transpositional perspective) would be to pick up the Kramnik repertoire volume on the dutch which also uses d4/c4/Nf3 setups.