The common criticism re: Wheelock's lack of sensible structure is probably justified—I'd have hated to have had to use it to learn Latin the first time around. As a refresher course, however, I found it worked well: it eschews the usual laborious ``puella est in cena'' type translation exercises in favour of actual Latin as she was spoke (``sententiae antiquae'') from the second chapter on, and while I can't imagine that being anything but frustrating to a half-interested ten-year-old, it gives you a sense of rapid progress as a revisitor.
A thing that Wheelock's Latin undoubtedly does better than my secondary school textbooks did is place Latin in context relative to other languages: almost every vocabulary item has a list of English derived words, and occasionally there are tables showing the development of Latin wordforms in modern Romance languages as well (including Romanian, which people in Western Europe tend to forget even exists). The introduction even (very briefly) discusses Proto-Indo-European! The flipside is that almost no effort is made to put Latin in its cultural and historical context—the history of Rome is left as a broad sketch, and Roman culture is only mentioned obliquely when it's relevant to the interpretation of certain passages.
If you learned Latin in (continental) Europe, things that may also upset you are the insistence on seeing the first person present indicative as the dictionary form of a verb (as opposed to the infinitive), the altered standard order of cases (nominative → genitive → dative → accusative → ablative → vocative, instead of nominative → vocative → accusative → genitive → dative → ablative†), the bizarrely Englishized terms for everything (gerund and gerundive instead of gerundium and gerundivum, imperfect and pluperfect instead of imperfectum and plusquamperfectum, &c.), and Wheelock's off-putting infatuation with the American military. Since this course was written for GIs returning from WW2, however, that last one, at least, was probably to be expected.
Another thing that caught me off guard was the inclusion of Latin Bible quotes among the sententiae antiquae, which made me realise that that's something my school never did, despite being a Catholic school.
On balance, though, I expected this to be a lot worse than it turned out to be. It's occasionally obvious that Wheelock, in contrast to most Europeans, isn't working out of an education tradition that never stopped teaching Latin since Latin was still a living language, but rather from the point of view that Latin is just an interesting thing to dabble in, but both approaches will get you to speaking Latin if that's where you want to get.
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† ``Rosa, rosae, rosae / rosam, rosa, rosa / rosae, rosarum, rosis / rosas, rosis, rosae'' doesn't scan; sorry, Jacques Brel.