Same engine. At least its the gasser not the NA diesel!
The 5 speed Lt77 is an improvement, but if power is your thing, a V8 conversion might be in your future. Personally, I'd keep the 4 cylinder until any other bugs in the Rover are dealt with. Its a simple reliable engine, if not especially powerful or economical
A friend of mine runs a land rover / range rover specialty repair shop. Based on his experience, they are capable of stopping anywhere, anytime, at any cost.
I don't know about the brakes, only their unreliability.