How radical was Locke on testimony?

Those familiar with the literature on testimony will recognize the following quote, from Locke's Essay Concerning Human Understanding, Bk. I, Chap. IV, Sec. 24:

we may as rationally hope to see with other men's eyes as to know by other men's understanding ... The floating of other men's opinions in our brains makes us not one jot the more knowing, though they happen to be true. What in them was science is in us but opiniatrety. (Quoted in C.A.J. Coady, Testimony, 14)

I was reminded of this passage from Locke while reading Steven Shapin's "The House of Experiment in Seventeenth-Century England." Shapin quotes Sprat, who, in his History of the Royal Society, noted that there was a division of labor among the members of the Society, with those particularly skilled in experimentation responsible for carrying out experiments and reporting back on the results to the other members. Sprat writes:

Those, to whom the conduct of the Experiment is committed ... do (as it were) carry the eyes, and the imaginations of the whole company into the Laboratory with them." (Quoted in Shapin.)

What was initially striking for me about this passage from Sprat should be obvious: Locke's own contemporaries in fact did not find it irrational to hope to "see with other men's eyes"!
The underlying position that Locke took with respect to testimony, however, is in some sense borne out by Sprat. Locke's main target in the passage quoted above is opinion -- i.e., the conclusions drawn as the result of experimental evidence. And here the traditions of the Royal Society seem to be more in line with Lockean prejudices. Again, quoting Sprat:

though the Experiment was but the private task of one or two, or some such small number; yet the conjecturing, and debating on its consequences, was still the employment of their full, and solemn Assemblies. (Quoted in Shapin.)

Of course, this partial defense of Locke relies on the distinction between observation statements and conjectures, etc., made on the basis of those statements (a distinction that Coady, in his discussions of historical figures in Testimony, criticizes a number of philosophers for making), but this version of Locke seems less immediately vulnerable to criticism, at the very least.