SilverFin is the only "Young Bond" book I have read, and I have been a bit disappointed by it. Although, I've heard this is not an uncommon opinion even among the fans of the Young Bond series, so I don't rule out reading other YB entries by C. Higson.
It's not a bad book, mind you, just more suitable for children than grown up people. Also, I must admit that to me the Bond universe is totally incompatible with the involvment of children, so I do have problems with the very idea of Young Bond, and therefore I am certainly not the kindest of judges here.
Yes, you'll definitely have to give Blood Fever
a shot, MkB. I remember being generally pleased (but by no means blown away) with SilverFin
after completing it, but Higson really kicks things into high gear for his next two Young Bond novels. Monumental improvements and definite standouts in the literary 007 canon.