In my very humble opinion, the only real "downside" about the 1/60s are their horrible legs. I'm not even complaining about the lack of a perfect transformation system (you have to remove the legs and re-attach them, same goes for the chest cover).
Other than that, I really dig their looks, their proportions, their size, their playability...
And, as some have said, it's the most "complete" Macross VF-1 collection.
Of course, there's also a "budget" issue. Depends on how much you can or are willing to spend.
But, say... if you were to own only one valkyrie, I'd pick a 1/48 (in my case, a Hikaru VF-1S... always been my fav. With Strike parts, too).