I thought he looked good against Leverkusen, got what, 20 minutes today? Didn't manage to pull off much, but I'm not sure Kane would do any better had he gotten on in the last 20 (not necessarily anyway). I think he's got what it takes to make it in the Prem. He's just off the pace of the league, needs to adjust to that. That's pretty much what every foreign player coming into the league says, "I needed a year to adjust to the tempo". Janssen coming from the Dutch league, it only makes sense. I'm sure he'll do it though, given time, and I'm sure he does it even quicker if people get behind the lad and support him. Not saying people aren't entitled to an opinion, of course, just don't let it seep into the stadium.
He does look a bit slow at the moment, but he also looks strong, moves well, and tries to find team mates in better positions all the time. AND! Please remember - he's most definitely lacking confidence for not having scored yet (in the league anyway). The pressure is mounting, and it's not a walk in the park to handle it for someone with his (little) experience. Give him time - who here expected him to slot right in from the start anyway?