Rick,
The Raven definitely does not have too much bass. If you hear a bass hump it will either be the tonearm match with the compliance of the cartridge. It could be the system but that you will know comparing it to a CD source you are familiar with.
I have played with 3 arms on mine and noticed that you hear everything you put into your system. This means that if the arm has a certain signature it will show. If the cartridge exacerbates the signature of the arm then it will show more. More likely than not if the arm is not high enough in mass the bass will become muddy. If the arm and cartridge match is truly synergistic it will shine. I honestly believe that everyone here wondering if the Brinkman Balance, LaGrange, Galiber or TW Acustic are better or worse are spliting hairs as they are all top flight. It is a matter of design and flexibility at this level. The Raven sound can be changed by the addition of a mat. So can the Balance. In the end of the day the bearing is the most critical. The bearing needs to optimized to the weight of the platter etc.
PS the Raven manufacturing process is a full in house operation. Thomas (the designer of the Raven) does not want to farm anything out to reduce cost as this will reduce quality. His bearing and bearing sleaves are made one at a time and matched. This means you can not just replace the bearing. You must replace both if you damage it (it is almost impossible to damage). You should look at the TW website.
Also, there is a lot of exceptional audio equipment that has long waiting list due to the fact that they are made in house and the quality control is at a very high level.