>>10495616/b/ has been completely taken over by various factions of normalfags at this point at this point due to its prominence in U.S. news cycles over the years, and is little more than a very fast-moving but very, VERY low-quality porn board. It also functions as a de facto second /trash/, since many of the most retarded people on 4chan prefer to post there.
/bant/ in its first days was pretty much the destination of a mass exodus from /b/ that drained all of the remaining quality from the latter board, leaving it in the state it's in today once and for all (although it was 90–95% of the way there already). For maybe half a year or so, it briefly recaptured something of the old charm of middle ages /b/. Now it's just a board for lonely gay teenaged boys who really like all the moe/slice-of-life anime that your country dumps on the world every three months, but who aren't butthurt enough about life to default to /r9k/.
I wouldn't recommend either if you haven't already fallen irretrievably into the habit of visiting one or the other, but if you insist, /bant/ is probably the lesser evil.
