I've always been hesitant to believe the ET explanation for Roswell for the same reason that the grandmaster of ufology, Jacques Vallee, is: the ufonauts seem too damn sophisticated to "crash" accidentally--and leave bodies behind, besides. So if what happened at Roswell in the first week of July '47 really did involve aliens (whether interdimensional or extraterrestrial), then it seems likely that it would had to have been done entirely intentionally, to see how we'd respond (or for some similar purpose).
It's also always seemed unlikely to me that the US military actually knows what's going on better than serious civilian ufologists, and far more likely that since 1947 they've been committed to presenting an appearance of knowing far more than they actually do (so that the general populace thinks the UFO phenomonon is either completely bogus, or that the military knows what's up and keeping it under wraps; in either case, the impression will be that everything is under control, and we won't have to worry that our powerful leaders are actually as much at a loss as anyone else). The "leaked" documents over the past few decades (MJ-12, etc.), the hype around Area 51, and the transparently absurd "crash dummies" explanation the USAF gave in 1997 for the Roswell bodies seem to support this idea--that elements of the government want us to think they've actually got space aliens to hide. It would work to their advantage in many ways--particularly in keeping classified projects hidden under the mask of "ET spaceships," which keeps the UFO believers happy and the UFO disbelievers scoffing at any such assertions. Meanwhile, advanced military technology can quietly go about its business, either believed to be something it's not or dismissed outright as not worth paying attention to, but in neither case examined more closely for what it actually is.
I think Nick Redfern's "Body Snatchers" is a tremendous contribution to the Roswell mythos, despite Stanton Friedman's scathing review (on his website) to the contrary. Friedman is a hero of mine (his Roswell books "Crash at Corona" and "Top Secret/Majic" are some of the best-researched, sensible approaches to this mystery out there), so I'd initially sided with him on his analysis of this book when it first came out. But last year I decided to take a closer look at Redfern's work myself, and I'm glad I did. Redfern's explanation, while perhaps a bit hard to believe itself, seems to present the most plausible explanation yet for what happened at Roswell. Ufologists say, "If it was just a Project Mogul balloon train, as the air force insists, then why all the military secrecy and panic around the time of the incident? What of the Ramey memorandum, the eyewitness accounts of small "Oriental" bodies, etc.? And why did the Roswell Army Air Field seem to not know anything about it beforehand?" But if, as Redfern contends, it was a top-secret high-altitude military experiment launched from Los Alamos, NM, involving deformed Japanese POWs, then the heinous nature of such an experiment-gone-awry is reason enough for the decades of secrecy, and it explains both the panic, confusion, and the Asian bodies in a way that makes a great deal of sense without invoking our friendly neighborhood visitors. Redfern's explanation for the origin of Majestic 12 was another clincher for me; it made total sense and smacked of exactly the kind of humor certain members of the US intelligence agency have no doubt been delighting in--and taunting sincere ufologists with--for decades (shameless bastards that they are).
Read it, open your mind, and think for yourself... I still don't know what actually happened, but I have a better overview of the possibilities thanks to Redfern, and for that I'm grateful for his efforts.