The Parterre has stellar build quality since all of the FitEars are hand made out of layers of acrylic in Suyama's lab by extremely competent technicians. There's actually this huge wait list in Japan for any of the FitEars simply cause they can't keep up with demand and they have trouble hiring techs that meet their standard. Although I believe that they are transitioning to 3D printing now which should eventually help with availability
The signature of the Parterre is a definite U shape to my ears. It's not my kind of sig personally, as I find there's simply too much bass and I find it's intrusive. It's usually okay until you hit something that focuses on bass such as EDM or something and then it just feels overbearing. The bass has very good extension and pretty good control, but it has a mildly lengthy decay and feels slow and lacks texture to me coming from stuff like the UERM. The treble extension is pretty good, and the mids feel a touch recessed due to the U shape. The upper mid/treble area felt pretty good to me when I demoed them. Not harsh, but just the right amount of aggression and presence.
I'd pass on the ASG-2 personally. It does sound similar to the 334, but the 334 is overall more transparent and has noticeably better imaging. I think the thing that impressed me the most about the 334 was its imaging. It was one of the few IEMs I'd ever heard where it felt like the stage actually possessed this chameleonic quality where it felt like its dimensions and shape actually changed depending upon the recording. It was very holographic in that sense. The midrange felt very transparent as well, but I wasn't a fan of its limited treble extension and sluggish bass. The G-2 on the other hand, has too much mid bass, and the treble has this sort of spitty quality to it due to a dip in the lower treble and a spike at around 8-10 kHz. The ASG-2.5 is overall much better sounding to me.
...Which brings me to the ASG 1 Plus. This is easily the best ASG phone that AS has put out IMO. The signature is significantly more neutral than its forebears, so everything from the bass to the mids to the treble feel quite a bit smoother and refined. It lacks the overall rawness of the Rockets which I really liked though.
I posted some impressions on it here:
http://www.head-fi.org/t/745498/aur...-information-and-discussions/30#post_11197280
Now that I've had a few days with it, none of my opinions on the Plus have changed since then, especially in regard to the upper mid/lower treble dip which is the sole area I have a beef with. I felt like this was executed better on the Rockets which have overall better linearity as a result. This results in some tonal issues with stuff like guitars and singers whose range is in the upper registers. It sort of becomes a pick and choose scenario as a result. I'm not sure that the majority of listeners would even notice this though since it really depends on what sort of gear you're coming from, and also because the industry at large seems to favor a signature with a dip at 4-5 kHz anyway.
Still, given my choice between the two, and my overall taste, I'd still pick the 1 Plus over the Parterre any day. It's also quite a bit cheaper at $396 if you order through Springtree. If you're ever in Japan though, see if you can demo a pair of the FitEars at some place like E-Earphone or Fujiya