I'm only halfway through the first chapter, but so far the text is among the clearest of any technical text that I've come across in my life. The authors correctly note that advanced technical texts have a problem with parsimonious notation - specifically, formulas are either so short that they imprecisely represent what's going on, or they're so long that it's difficult to make heads or tails of the formula from first glance. The text appropriately repeats formulas to aid learning and carefully footnotes any possible pain points readers might face. Lovely.
And for the folks complaining about installing scheme and scmutils - download VMWare or virtualbox, install Ubuntu as a VM, and follow the page of instructions to install scmutils. Yes, it's annoying to have to sudo to do stuff, but this is also not the problem that it was when the book first came out since you can easily live with your current OS and urn this stuff.