Yes tmpgenc is a good prog. I'm sure you don't want to spend thousands to do better. Your cpu is probably the biggest difference. Tmpgenc can use hyperthreading as well as multiple cpu's. Basically, the faster the system the faster the encoding. Encoding can bring a dual cpu system to it's knees. Also many people swear that encoding to a second master drive helps.
Most people just let the encode process run overnite. For instance, I went from a 2.4 northwood to a 3.0 prescott and it only cut the encode time of a 2 hr dvd grade movie by about 1 hour.