Lallana has been fairly intergral to the way we've played, especially when we've had the three pronged attack of him, Firmino and Coutinho. Yes, his output isn't as high as it could be, but his contribution to the way we play shouldn't be understated either.
The ideal situation is that he stays and instead of having someone like Ibe or whoever coming on and looking well out of their depth, we have someone like Lallana who can step in and play a part whenever we need him to. If we buy another attacker and also with Ings and Origi returning, competition for places will be high, but it also means our quality will be also.
Overall he's been a good signing. There seems to be this myth with support attackers that, unless they're hitting 10+ goals and assists every season, they're a failure, people need to look at the stats of similar players in other top teams. Of course, you always want someone of real top Worldy quality who will weigh in with more than most, but put it this way, for all the adoration they've had in years gone by, I'd have Lallana any day of the week ahead of the likes of Nasri and Navas. His price might have been inflated, but he shouldn't be weighed down by that anymore (certainly not by certain fans who just won't let it go).
he's been a key player at times and deserves alot more respect for his ability and also his desire to do well for us.
Benteke I have sympathy for, as I've said before, but he has to go this Summer.