It depends on what you want to use it for. Primarily road use with the ability to go off road when needed......DefenderGrenadier over the "Defender" any day of the week.
Primarily off road, Overlanding or farm use, but still good on road......Grenadier
The Defender Commercial version works out a lot cheaper than a Grenadier if you're in business. Hopefully Ineos will get the Grenadier certified with HMRC for Commercial use but l think the U.K. is a fairly small part of lneos's plan and not a priority for them.