Finally catching up after our week away.
I think the cot bumper thing is that it stops air flow so could increase cot death risk, and its just another thing to get tangled up in.
Cot mattress - we've also got a sprung one with washable cover, going to use it third time round and similarly to whoever else commented its still got lots of life in it and is nice and firm. I've seen foam ones that have gone squishy with a dent in the middle and it doesn't look as supportive for the baby.
Cot beds/cots I would say it depends how soon you want to have a second baby! If you think you'll want a 2 ish year age gap then you'll need the cot again, so might aswell get a big bed for your older child and re-use the cot iyswim, whereas if you've got a cotbed then you won't get the use of the 'bed' function before you need it back as a cot for a baby.
Been feeling really rough the last few days, IBS playing up, and wondering if I've got low iron? Went to bed at the same time as the DCs last night and slept 13 hours (with wee breaks obviously!) My 28wk bloods were done 2 weeks ago and were fine, could I have become anaemic since then?!
So sorry for those with GD, rhesus -ve etc, and really sorry I can't offer any advice. Glad all those twins and wishwales baby are staying put!