I used to at least be able to recommend ThinkPads but I can't even do that anymore. I pretty much only have Macs left as an option at this point, but not one that I'm super thrilled about. I mostly use VPS and a $600 _should_ be fine.
I almost updated to the new one however they completely murdered it with the "adaptive" change. Capacitive function keys, home and end on the caps lock key, what _on earth_ were they thinking?
http://arstechnica.com/staff/2014/01/stop-trying-to-innovate...
On the more hardware nitty-gritty side of things though, nearly all of their laptops the last 4 years have heat problems, including one line that you can never use more than 50% of the CPU before it throttles due to severe overheat. My second-gen x100e is the second laptop I've ever used to actually give me a burn - and from doing nothing more than streaming a youtube video. Their x series are basically unusable and were the only ones I would consider buying to begin with.
Sorely disappointed.
Edit: Also their software is shit, but I don't use Windows on it anyway. They're still better than ASUS laptops though.
I really can't stand those. I've had the headphone jacks on two separate high-end Android phones go from crackly to completely unusable, while my ancient iPod nano is still rock solid after years of heavy use.
A decent 3.5mm jack is not an expensive part, but so many manufacturers seem to opt for the cheap garbage that doesn't actually work.
it's old fashioned, but I prefer them to be separated.
Even with the $600 core i5s, it'd be getting the same OS. Hopefully they've switched to the newer Intel wifi cards because the Linux driver on the 5400AGN they were using has problems.
(But I do talk with them back and forth to make sure a Chromebook will do everything they need.)