Hi Andy,
One of the advantages with the IBU2 is it works with every 4/6 channel out there and because of the radio to IBU2 calibration even a rubbish radio can be used with out side effects.
Like Shaun says I sell a load of radios here
http://www.rctankelectronics.com/store/ ... Parts.html
I started using the planet T5, but now selling mine because too basic compared to other newer cheaper systems.
Pros - Basic features so very easy to setup for a new person to radios. Only uses 4 AA batteries and even works well on rechargeable AA's. Return spring kit is available and less than £2
Cons - £50 for radio then £15+ for each receiver afterwards. No suitable for IBU2 Pro as only 5 channels
Then as I was selling IBU2 people moving from RX18 had no experience of hobby grade radios so started offering the 4 & 6 channel hobby king or flysky radios
Pros - Very cheap. 4 Channel basic controls so easy to setup. each brand receiver interchangeable. Receivers £10 or less, can get 2 from china for £15-16
Cons - Poorly made, I've found pots don't always transmit full 100% but like I said above the IBU2 compensates for this via the configuration. 6 channel version needs a programmer lead and plugging into computer to configure (I do this to all radios I sell so work with IBU2). No aftermarket source for return spring kit. At the moment I'm buying a 4 channel radio and breaking it down for parts to sell but not very cost effective.
Turnigy9X/Flysky9x/Turnigy9XR
These are 9 channels radios fully computerised radios with 8 channel receivers. Too many Pro's to list and only Con Is the stick return the 9X is as above radios and can use same part. The 9XR is different but Hobbyking sell a replacement gimbal for only a few £ and is easy to install
I know loads of people run these radios for the tanks, I prefer the above cheap 6 channel radios but no real reason just preference.
Upgrade 6 channel radio
I started selling these just before Christmas and are now my fave radio set, small, light computerised system with telemetry (with extra sensors can send info back to controller like voltage, speed etc)
Pros - Small, light, uses 4 AA batteries which appear to last forever (i'm still on first set in two months!) back lit digital display, can assign switchs or pots to channels 5&6 of receiver. receivers £6-10. can link 20 models in it's memory
Cons - no return spring set available yet. not quite same amount of settings as the 9x radios but close.
I know at end of day it's down to your own preference, from my experience and seeing how tech is moving on I say go for the Turnigy 9XR Pro (ask before you buy as you need extra bits, like a module) or the upgraded 6 channel. Both quite new tech and computerised so a firmware update can give you more features in the future and are suitable for most rc models not just tanks.
Ian.