Hi Anna Marie,
I changed from levemir to lantus at the beginning of the year. For me, levemir gave me great control but I developed a skin reaction to it. I went temporarily onto insulatard (which didn't suit me at all) and then onto lantus. I haven't had any problems with lantus, it has been fine for me. A friend has also been on it for some time now and has great results.
As we are all individual, so is our lifestyle, diabetes and management: if you give it a go and keep an eye on its effect, if it doesn't suit your son you can always try something else.
Let us know how you get on.
Jen