Do it!!! We recently put our almost 5 and almost 3 yo together.. best thing we ever did!! Miss 3 has an awesome routine and goes to sleep with ease where as Mr 5 is terrible and will cry and tantrum if left alone etc and usually ended up with DH in my bed!! Since moving them together things have been great, he isnt alone so he feels secure and he just does what Miss 3 does and and goes to sleep!!!! Now we just have to refine the actual bed TIME (still too late at night) and i will be really happy!!