The early versions of the ECR88 were a bit troublesome in terms of cooling capacity. If your buying a new machine, this issues have been sorted by upping the fan speed and also increasing the size of the cooling package and vents on the engine covers. Big benefit of the ECR88 is the cabin. Both the ECR58 and ECR88 share the same cabin and I doubt there's anything bigger in that size on the market.
If buying used - make sure it has the updated cooling package, because if you live in hot or humid conditions, the machine will struggle to cool itself. Despite this - good solid machine, with a very reliable Yanmar/Volvo donk that won't give you any hassles.