Comments to a post earlier this summer raised some well-known issues of how some US-based and some non-US-based researchers view each other in terms of work hours/work ethic.
It would seem that some researchers based outside the US (e.g., in Europe) think that those in the US have to work crazy-long hours with few vacations just to stay afloat, much less succeed. In this workaholic system, it is difficult to have a life outside of work. US researchers (faculty, postdocs, grad students) are prisoners of the extreme demands of endless work.
On the other hand, it would seem that some US-based researchers are incredulous at the vacation-laden work schedules of some of our international colleagues, including some international graduate students and postdocs who have particular expectations about summer vacation time.
I don't think a discussion about which is "better" (for individuals or for academia) would be very productive or interesting. I am more interested in discussing how/whether we can find ways to work together, even if we have vastly different philosophies about vacation time.
I have never found it to be a major problem to work with colleagues who disappear every August. I am hyper enough about my research that I am sometimes annoyed if a colleague disappears to their (apparently internetless) ancestral home and this delays submission of a manuscript, but a month isn't a big deal in the overall scheme of things. I don't want to take a month off in the summer myself, but I can work with colleagues who do.
That last statement becomes somewhat less true if the individual in question is a graduate student or postdoc who disappears for a month in the summer.
Graduate students who are not on a fellowship may have their funding separated into an academic year part and a summer part. The academic year part may be paid from one of my grants or it may be paid entirely or in part by the department/university (e.g., for teaching). In the summer months, however, I am almost always responsible for paying my students an RA salary (+ benefits). Some students might TA a summer course and some might also be paid from the grant of a co-adviser, but somehow I need to organize things so that my graduate students are paid in the summer months.
Summer is the time for getting a lot done. Graduate students rarely take summer classes, and, unlike during the academic year, there are few other distractions. Therefore, if a student is being paid from a grant to work in the summer, and if this is the time to make maximum progress on thesis research, taking a month off can be a problem.
Some students do it anyway. If a student really wants/needs to go home for a month in the summer, we can usually work that out to make it possible. Ideally, the student will have made excellent progress already and can afford (in time) to take a vacation. If progress has not been so great, taking an entire month off each summer might mean that the student's funding runs out before they finish their thesis research, and that's a problem for everyone. These things should be discussed.
So, my overall philosophy about people who disappear for a month in the summer: (1) colleagues: OK, I can deal with that; (2) students or postdocs paid from a grant: maybe not OK, but it is not impossible. If it does occur, the vacationing person will ideally deal with any major deadlines or other issues that arise during the time away, and not completely disappear off the grid.
If you advise graduate students or postdocs and support them on grants in the summer, what is your policy regarding long vacations? I am not talking about a couple of weeks off; everyone should be able to do that. I am talking about those who go away for a month and do not make any research progress during that time. Some may not even communicate at all during that time. Is that OK with you/not OK with you? Why or why not?