The Ortofon Blue is a nude eliptical. Both the Sumiko Rainier and Olympia (the upgraded stylus they are sending) are lesser quality. Elliptical bonded to a post, then mounted on the cantilever. Not sure the actual name of that. But if to my ears, I cannot tell the difference, should I care? Also to consider is that the O Blue has been used for a year and a half. Is it still a no-brainer that I keep the Sumiko? I think so. I just want to know if I am on the right track.
The theory behind using a nude elliptical tip is that its moving mass is lower, so it will track better. Think in terms of a car's suspension- lower mass suspension components like control arms/brakes/hubs, wheels and tires maintain road contact better and this is referred to as the 'unsprung weight'.
The differences could be seen on an oscilloscope more easily than heard, in many cases. Plus, the tracking errors won't be audible on every song, every LP- it's only the most dynamic passages that cause the stylus to leave the surface, assuming the cartridge is a good match to the tonearm WRT compliance & mass and it's correctly set up.
When I started using my turntable after actually seeing the tip with my microscope, I decided to buy a second headshell and mount the Audio Technica cartridge that had been used for, maybe, ten hours. When that arrived, I adjusted it according to the three test records and listened to the tracks, making corrections as needed. Then, I was able to compare. It's not an instantaneous test- I need to remove each cartridge and insert the other and set the tracking weight, then adjust the level because the output from one is much lower than the AT. The same tracks were played and I made notes about bass, mids, treble sounds and impressions about the sound of various instruments. Mine definitely sound different and with the bass being a bit stronger from the AT, it's a good choice when the LP might be a bit weak in that range of frequencies.
I like having an option but the fact is, I rarely switch because the Denon sounds really good. That said, I enjoyed the AT when I used it.
It takes time to really hear the differences. Sometimes, it involves separation, balance of frequencies, an instrument may sound better using one or the other or one can create the impression that the instrument is "in the room".