Go with whatever you want really. spending on your RC Control frequency etc
I always use 2.4Ghz for long flights, in the UK I cant get past 5km with 5.8Ghz ( Airwave based units ) so I use that for close range flights. I use Immersion exclusively but no transmitters are in stock anywhere until the nextwave new versions are released. Then the 5.8 range should be a lot further over here.
We are going a bit off topic though for an X8 thread, pm me if you want though