Beast Mode: Sludge looks very G1, though silver would look much better than gray.
Robot Mode: In robot mode Sludge has a great head sculpt. His tail turns into a giant sword rather than hanging off him like the G1. I just wish he had a few more paint apps.
Overall: Sludge looks great, and is a worthy addition to any Dinobot collection. I highly recommend him.
Thanks for reading!