I've seen a couple comments against Behind the Claw - what exactly is the problem? (Other than silly amounts of errata.)
Two problems: 1) The amount of errata is far too low (i.e. there are a lot of discrepancies with previously published material that hasn't been errata'ed). 2) There are a number of internal inconsistencies.
I don't have BtC at hand today, so I won't list any examples, but if you've read through BtC without saying "Huh?!?" to yourself quite a lot, I suggest you try reading it again...
To be fair, some of the inconsistencies are what I call "legacy problems", i.e. inconsistencies introduced by previously published material. The authors were not asked to correct those inconsistencies, and might not have been allowed to do so if they had tried.
And keep in mind that I fully expect to never see a copy of The Spinward Marches Campaign, much less own a copy.
If you don't know about the discrepancies and don't mind the inconsistencies (or disagree that they are inconsistencies), then there's absolutely no problem with BtC
for you. There's no earthly reason why you should care about previous canon, except that if you base your TU on some statement from, say, BtC, and someone else writes an adventure based on the previously published information that BtC ignored, you won't be able to use that adventure. That may or may not be something you give a fig about.
My biggest problem with BtC is that it's hard enough to keep a shared universe self-consistent when everybody respects what earlier authors did. It becomes much harder if new authors feel entitled to change things around for no better reason than they like their own ideas better. Please note that I'm not saying that there aren't legitimate reasons to retcon previously published material[*], just that "I like my idea better" isn't one of them. Even there I'm not a fanatic. If a sparkling new idea makes for a vastly better RPG setting, then I'm all for it. But 'slightly better' isn't enough to outweigh the inconvenience of changing things around.
[*] Hey, there are CT bits that I blame BtC (and Marc Miller) for NOT changing

.
If you want to be able to use Traveller material produced by other people (fans and professionals alike), you have a better chance if you and they both stick as closely to the same shared universe as possible. You are not obliged to stick to canon, but if you don't, you've no complaint coming when some future product proves incompatible with what you've established in your TU.
The people who write stuff for publication, OTOH, is IMO obliged to stick to it. So when new material contradicts previously published material for no better reason than the author didn't get his facts straight (and I sort of doubt that ALL the differences between BtC and PPM were deliberate

), I feel I DO have a complaint coming. Note the 'for no better reason' bit. If the new material fixes a problem with previous canon, I not only applaud it, I feel I have a complaint coming if it doesn't ;-).
Hans