The big article (Comparison of General American and Received Pronunciation) seems much more substantial. Indeed, it takes a long time to get to grips with what it has to say. It starts with a comparative treatment of stress differences. The writer introduces a system of superscript and subscript letters and numbers so that s/he can indicate cases where, for example, the pronunciation given as BrE is also the most common variant in AmE, while subscript a or b means that “the relevant unstressed vowel is also reduced to /ə/ or /ᵻ/ in AmE or BrE, respectively” (I don’t understand the last sentence). The stress section starts with French loanwords, and we are told “French loanwords that differ in stress only are listed below”. However, examples such as ‘beret’ don’t seem to fit this – the word is given pronunciations in a note “ US /bəˈreɪ/, UK /ˈbɛreɪ/”, which in addition to the stress difference looks pretty much like a vowel difference to me. Further on, we get words cited as loanwords that only qualify as such if you can go back many centuries – e.g. ‘address’, ‘decade’. The inclusion of vowel reduction in this treatment is pretty hard to interpret – try this one (where American is initial-stressed and British is final-stressed): ((bi)p)artisana.B1/2[nb 18] seems to cover ‘bipartisan’, ‘partisan’ and ‘artisan’, if I interpret the bracketing correctly; subscript a means there is vowel reduction, then B1/2 seems to mean that “the pronunciation given as AmE is also the most common variant in BrE” while at the same time “the AmE pronunciation of the word is a common variant in BrE”. NB18 takes us to a note that “Only the middle vowel is reduced in the BrE pronunciations”, but I can’t see any sign of vowel reduction here.
As is well known, WP doesn’t allow material in an article that has not previously been published – such material is classed as “original research (OR)”. A WP editor has flagged an OR issue with this article, and you can see why. After a couple of sections dealing with affixes, the article moves on to segmental differences. Most of this material seems OK, though it is hard to see how it could be used easily since the table entries are given in an odd order (most WP accounts of English phonemes list them in an order that corresponds roughly to the symbols' resemblance to letters of the alphabet, so /a/ comes before /i/, /b/ before /p/ and so on.)
I have added references to the most important pronunciation dictionaries in the section “Further Reading”, but I don’t suppose anyone will take any notice, since they are not available free on line.