The verdict;
The 103R is a clear winner. It is all because of the purer wire and the lighter coils, as compared to the 103. With proper loading applied both cartridges like 400 plus ohms with the 103R's ideal load @ 600 to 700 (I use 690) ohms, only your ears know for sure.
The 103 will perform very well (better than the 103R with a 100 ohm load) without it's ideal load, so you can enjoy a 103 cartridge even without its perfect settings. Many people have proven this true throughout the years. The Denon 103 was introduced in 1962 and tens of thousands have marveled at this wonderful cartridge with all manner of circuits, loads and SUT's.
What do I think of the sound? The Pulse Guard R (103R) improves on every parameter and eliminates all of the bad and or distorted sounds that come from a stock 103R or 103. By the way if you do not remove 90% or more of the plastic surrounding the motor assembly you will NOT achieve what I am talking about, which is why wood bodies and others are vastly inferior to the Pulse Guard when trying to extract ALL that the 103's can do. Wood bodies press fit into place or tape or use a dab of glue or screw leaving all or most of the plastic I am talking about. There is also no extra damping or encapsulation to eliminate these distortions. I have even potted wood bodies in an effort to reach the full potential with the micro dampers and they still fall incredibly short of the 103's maximum potential. I also think that most MC cartridges on the market would improve if they damped and encapsulated their motors and yes I am referring to $10k cartridges. Leaving the motor assembly exposed to the environment is not the way to get the best sound possible from anything much less tiny moving coils in a magnetic field, why do you think so many manufactures use various materials (wood, rock, various metals screws etc...) to try to "tune" the sound. Just eliminate the issues and you're miles ahead.
I am also a fan of holographic imaging (see Jason Serinus comments in Awards section) as real music has when at an event, if a cartridge can't image properly then it is useless to me. An actual review is in order but that is for another page and another time as I prefer for you to tell me what you think about the Pulse Guard's performance.
Now I am only concerned with the best sound I can get from my records and the value of a component. This is the reason for the Pulse Guard body its removal of all the excess plastic, encapsulation, micro damping and the Sapphire cantilever with Micro Ridge diamond (SMR) $1100-. I would like the Pulse Guard R SMR to sound as good the best cartridges available like Ortofon, Benz Micro, Koetsu, Ikeda, Clearaudio, Soundsmith, Shelter, Lyra, Air Tight, etc... to only name a few and the SMR stacks up very well with the best of these. I go to Audio shows regularly (I bring great records so my source is the same) and listen to the best available. The Pulse Guard R MR Sapphire can compete with the best. The strengths of the 103R motor is it's balance, faithfulness to the music and great dimensionality. I own and use a Benz Micro LPS as our reference cartridge and it is better than the Guard R SMR but not to the degree you may think. If rating these two cartridges the SMR would get an 8 out of 10 and the LPS a 10 out of 10. Just for reference a Benz Micro Gullwing SLR ($3.6k) rates a 8/8.5 out of 10. The LPS has better detail and is fuller with better dimensional boundaries, all the things that make reproduced music so special. But look at the price difference $1100 vs $6k and without a system that can show all of these differences the extra money is a waste. The Pulse Guard R SMR is the best bargain in all of the MC cartridges available.
To the 103R's credit it continues to evolve and improve it's performance with each new modification. I do not think the 103R is done even now (Pulse Guard body, 40 micro dampers, Sapphire cantilever and MR diamond) it keeps getting better and I have not even begun experimenting with the magnet yet, stay tuned for more.
Click in this section and go to Vinyl Engine for information on Denon cartridges and the many 103 versions.