We are part time co sleepers as well....he has his hammock and usually starts out his night in there and if he is unsettled after any feed during the night he comes into bed with us....we also have the first years safe sleeper but have only used it a handful of times...bubs did not like it as if he was unsettled he wanted/needed body contact with one of us to reassure hin that we were there...we should probably retry it now he is a it bigger...he would probably be okay in there now. He is usually just in between us but occasionally has the grizzles and needs the cuddles comfort to help him drop off again...it is not unusual for me to wake up 3 hours with a dead arm......lol....
I see nothing wrong with it...it is ressuring for bubba and means we get more sleep rather than spending 2-3hours trying to resettle a bub in the wee hours (we learnt this the hard way after hubby tried this tactic when bubs first came home....wasn't long before he realised he would get more sleep if he just brought him into bed with us)....