As far as I can tell the X18/XR18 are functionally identical apart from some minor differences in the I/O connectors: [INDENT]* X18 has TRS Aux outputs. XR18 has XLR Aux ouptuts[/INDENT] [INDENT]* X18 has RCA connectors on Channels 17/18, XR18 has TRS[/INDENT] I was wondering if there were any other differences (apart from the form factor) to justify the big price difference in the UK where the X18 costs about 75% of the XR18 price? I can accept that the XR18 is a more usefully shaped box for life on stage, but would the X18 be less likely to survive if it was plonked on stage anyway? Is there a big difference in the construction of the casing e.g. metal versus plastic versus rubber? I'm basically looking to save some cash and wondering if the X18 is actually much more fragile than the XR18.