>My biggest issue, though, is environmental - how much of what's in there is easily recyclable, and how much is toxic - or potentially toxic…?
First up, making laptops that are are reliable and more powerful than the user needs increases their life and reduces the amount of recycling required. The longer a laptop battery lasts on one charge reduces the number of charging cycles over a year, meaning that the lifetime of the battery will be longer. The same goes for repairing - although Macbooks are tricky for amateurs to repair, Apple can repair them and sell refurbished units. Not ideal for some owners, but better than nothing.
Secondly: The less material and components in a machine, the less recycling is required. SSDs contain less material than spinning rust HDDs, laptops without an optical drive contain less material than those with them, etc.
Okay, onto recycling: The cases are aluminium. Non toxic, easily recyclable. By using glue instead of screws, the human labour of reducing a laptop to its constituent parts is reduced - batch process in an oven, or continually process on a conveyor belt through an oven.
That said, here is a Wired.com opinion piece that disagrees with everything I have just said. Personally, I would be worried if a Wired article agreed with me. You can judge for yourself the validity of their arguments: http://www.wired.com/2012/10/apple-and-epeat-greenwashing/
Toxicity: These days toxic materials are more of an issue during the manufacture of laptops than they an hazard within a laptop - people have more experience of using lead-free solder, and screen backlights are no longer the CCFL type that contain mercury. Green Peace seem optimistic: http://greenpeaceblogs.org/2014/08/15/apple-takes-first-steps-detox-manufacturing-supply-chain/