Some experiments, all under hu: in Wikipedia. A possible conclusion is that some API limit is broken at pages with long history while for short histories the results are identical.
site = pywikibot.getSite() page = pywikibot.Page(site, what) print len(page.getVersionHistory(getAll=True, reverseOrder=True)) print len(page.fullVersionHistory(getAll=True, reverseOrder=True))
what = u'Földvár (építmény)' 68 68
what = u'Triatlon' 127 127
what = u'Magyarország' (This is the "Hungary" article in huwiki with many edits.) 3510 812
what = u'User:BinBot/try' (This is not big but has several edits. In this case getVersionHistory() also takes some minutes!) 53833 2902
what = u'Wikipédia:Kocsmafal (egyéb)' (This is the main village pump of huwiki, several times edited a day.) 48155 156
In the last two cases getVersionHistory()was very slow and fullVersionHistory fast but erroneous.
Let's try some other wikis: what = u'en:Triathlon' 2039 893
what = u'de:Szeged' 528 528
what = u'de:Berlin' 7041 912