I went through the process of leaving a PhD program just before the dissertation phase. I have not experienced any negative impact from this in job searching or interviewing. In fact, in some cases the interviewers have joked about how leaving early must imply that I actually have some common sense.
I wrote up some thoughts on the mathematics StackExchange site that might be relevant for this thread too.
In general, just be honest. Try to leave your PhD group on the best terms possible. Connect with peers and professors as much as you can before leaving (via LinkedIn, or swapping emails, etc.). Ask them point blank if you can count on a positive reference if you ever needed one.
If you leave on bad terms (e.g. your adviser is furious that you are leaving, or you leave without completing a certain milestone that causes everyone else to absorb more work) then it can be trickier but still not impossible.
Be honest when describing your motivations. Experiencing industrial work settings and preferring that to an academic setting is a very mature and valid reason to switch. If someone holds that against you, then you get free info that they would be a horrible boss.
I do list my lab experience on my resume. I completed several useful and interesting projects in my time as a PhD candidate, so I like to talk about these during interviews if I can. Having them on the resume does sometimes lead to confusion, so just be sure to practice a nicely worded and clear statement that explains why the resume items are there and what your thinking was in terms of leaving the PhD program.