Having used Kentmere 400 in 135, I'd agree that it doesn't push as well as HP5+ and since recent years have seen me doing a *lot* of shooting in a dim jazz club, the Kentmere wouldn't be my film of choice. That said, I took a roll of Kentmere 400 on my recent trip to Arkansas and it did a great job of photographing forests and making family portraits.
It is an excellent all round film, pushes to 800 nicely and can be used for pretty much anything other than dim jazz clubs or brightly lit funfairs. Harman has better brand visibility than Foma so the Kentmere is likely to be stocked by many more retailers than Foma. And some still fear Foma's quality control. This is likely a winner for Harman and the Kentmere brand. It is appreciably cheaper than FP4+ or HP5+ and for most users, especially those getting into film, it's effectively interchangeable with those.