It's almost funny to see the same sort of issues that you've had over in the UK about the wishes of some to adopt the AR15/M4 style wpn system are almost mirrored over here. Here it's partly put down to SF envy where the line battalions see the SF lads with the cool gear and want it too. We've now got the latest home grown variant of the old Steyr AUG, the EF88 in service and it seems to have fixed a lot of the issues with the previous models around weight and modularity (is that a word). The SF lot will retain the M4 wpn systems as it better suits their needs, especially when you consider justification points like compatibility with allied forces supply systems etc. There's been a reasonably good paper written on the whole F88 introduction into service, its ongoing evolution and the ongoing angst it's caused in some sections of the Army, I'll try and find the link.