ELT's were a thorny problem down here. Some 6-7 years ago, CASA mandated for ELT's to be fitted to all aircraft. AOPA ran a heavy campaign against, arguing the number of times that 'fixed' ELT's were of no use, either sinking with the airframe after ditching, or burning, or just getting wrecked in the crash. They proposed that a choice be allowed, of either portable (which theoretically would remain with the pilot, and therefore always be useable) or fixed. CASA got rolled, and the requirement was rescinded in favour of AOPA's option.
I have 6 axis fixed ELT's in all my machines, plus plenty of portables. There is a quite comprehensive Advisory Pub. from CASA which deals with preferred installation issues for fixed ELT's, eg shortest possible antennae cable run, main unit to be buried in main airframe structure, no cable run to pass through points where structure may fail and break the cable, etc. 6 axis ELT costs (IIRC) about $A1000, installation varies on complexity, but budget about $A2k. Battery usually requires replacing 2 yearly.
Cheap, affordable safety. What's the issue?