Blackie. I've never done a head-to-head comparison of these two pieces, but I have owned the Moon I-5 for almost a year. My only experience with Plinius gear was early last year in a store and they sounded great. You might want to do a search on this, because there have been some threads addressing the I-5 vs. the 8150.
Everything I've read here describes the Sim Audio as being more neutral and possessing greater detail than the 8150, and my experience with the I-5 supports that. People seem to feel the Plinius 8150 is warmer, however there have been some posts here that suggest the 8200 is a whole different animal. The new unit from what I've read seems to have moved closer in sound characteritics to the Moon I-5.
If you are put off by a bright sounding system, I would caution you to pick your associated equipment with care when it comes to the I-5. Since owning the Sim Audio I have upgraded all parts of my system in order to get the sound to where I am content. While not in itself a bright amp, I most enjoy the I-5 when I use copper cables with it such as Analysis Plus Oval 9 and Cardas Golden Cross. Switching from DH Labs to these products has resulted in a much fuller and more organic sound. I'm also using a Theta Pearl transport and a Bel Canto DAC 1.1 with the Sim. I'm sure the refined nature of these pieces has helped too, so much so that Kimber Illuminations D60 digital cable doesn't sound bright in my setup at all.
What I like most about the Moon I-5 is the wide and deep soundstage it throws along with it's great sense of air. The sound is very alive. I didn't want to handcuff these characteristics, so I have taken the approach of attenuating any nasties with complimentary cables and associated gear. I've gotten my setup to a point where I can enjoy it's musicality and also it's excellent low level detail, but it took a lot of experimenting, tweaking, and upgrading to get there.
In my 12 x 16 foot room, the Moon I-5 plays my ProAc Tablette 50 Signatures plenty loud. I feel no need for more power. These are small mini monitors though, and I'm sure the 8200 would do a better job of driving floor standers.
I hope this helps a bit. I'm sure when you check out the other threads and read any reviews on the 8200 it'll all crystalize for you.
Everything I've read here describes the Sim Audio as being more neutral and possessing greater detail than the 8150, and my experience with the I-5 supports that. People seem to feel the Plinius 8150 is warmer, however there have been some posts here that suggest the 8200 is a whole different animal. The new unit from what I've read seems to have moved closer in sound characteritics to the Moon I-5.
If you are put off by a bright sounding system, I would caution you to pick your associated equipment with care when it comes to the I-5. Since owning the Sim Audio I have upgraded all parts of my system in order to get the sound to where I am content. While not in itself a bright amp, I most enjoy the I-5 when I use copper cables with it such as Analysis Plus Oval 9 and Cardas Golden Cross. Switching from DH Labs to these products has resulted in a much fuller and more organic sound. I'm also using a Theta Pearl transport and a Bel Canto DAC 1.1 with the Sim. I'm sure the refined nature of these pieces has helped too, so much so that Kimber Illuminations D60 digital cable doesn't sound bright in my setup at all.
What I like most about the Moon I-5 is the wide and deep soundstage it throws along with it's great sense of air. The sound is very alive. I didn't want to handcuff these characteristics, so I have taken the approach of attenuating any nasties with complimentary cables and associated gear. I've gotten my setup to a point where I can enjoy it's musicality and also it's excellent low level detail, but it took a lot of experimenting, tweaking, and upgrading to get there.
In my 12 x 16 foot room, the Moon I-5 plays my ProAc Tablette 50 Signatures plenty loud. I feel no need for more power. These are small mini monitors though, and I'm sure the 8200 would do a better job of driving floor standers.
I hope this helps a bit. I'm sure when you check out the other threads and read any reviews on the 8200 it'll all crystalize for you.