From what I have seen of Lowell this year, he is more mobile than he was last year. And his hands are exceptional, as always.
As far as Beltre goes, who knows? Like Renteria and Lugo, he has fallen into an early fielding funk here. Will he come out of it? Personally, I doubt it. He will press harder and harder to prove himself and it will have the same result as Renteria, in my opinion.
That's as good an answer as I can give right now.