[shotgunshane]

@kylezo, I received your PM. It's a little difficult to give you a recommendation without knowing what kind of sound signature you are looking for or what your preferences are on the different parts of the sound spectrum. Coming from the older M5, I'd say the safest bet is to replace it with the new m5 with mg7 driver. It should improve upon the old mids and treble by a noticeable difference. The increased treble presence should not only improve dynamics over the old but soundstage and imaging as well. 
 
If you want to try something different, the first thing to realize is you are not going to get the same level of sub bass quantity and quality in most other offerings. The two I would suggest are the FXT90 and GR07. Both will be a lot brighter in overall presentation from the old m5. The FXT90 is a mid centric presentation, so vocals can sound more intimate and it has great instrument realism and dynamics. The GR07 is a more monitor like presentation with very good balance across the spectrum. It has a little more sub bass rumble than the FXT90 but has less overall bass quantity. of the two I prefer the FXT90 for better dynamics and timbre but both are very good choices. 
 
The TF10, being BA based, is a much bigger departure from the Atrio sound. BA bass doesn't come close to giving the rumble and texture of a dynamic driver in universal housings. While the TF10 treble is pretty great in my book, I'd much rather have the mg7 based Atrios but this is due to my personal preferences and not everyone would agree. 

 

[kylezo]

Thanks for your insight Shane. I'm definitely down to either the MG7, FXT90, or GR07 at this point. To me, it's a matter of MG7 = safe and cheap, FXT90 = colored musical signature, GR07 = more on the balanced, analytical side. Just comes down to if I want a departure from my previous sound, and if so, what kind of a risk I want to take into new territory. They are all great phones so I'm sure I won't be disappointed in any case. I absolutely want to nurture my addiction by trying out new sounds, so I think I'll probably end up with one of the 2 new (to me) sound signatures. I'll look again at the overall fit and build quality of the 2 and probably make a decision pretty soon.
 
Thanks again