you also might want to read up on JVCs HA-FXT90s, they sound as if they will have alot of what the EX series offers, but with less bright and sibilant treble? I will be picking up a pair soon, and insted of multi BAs, you listen with multi dynamic drivers! (well two), and at a cost of around $130.00 they seem as if they would be a good bang/listen for the buck!
I loved the TF10s, and like I said they were an awesome intro into the world of Higher-Fi, but....they are from an older class of IEMs, and the industry seems to have made some significant breakthroughs in the world of IEM sound since the birth of the TF10? but BAs an DDs each offer something the other can't, so it depends on what you listen to music wise, and what will benefit you the most!
I've discovered from going in the direction of starting out with the TF10s, and then going to the RE series, that the 10s sounded muddy after listening to the 262s, and I just couldn't go back to them, ugh! and from there onto the EX600s, all very great IEMs, I look at it as growing into a sound that I discover and wind up liking the most, we all have to start somewhere
but if you do get a set of the TF10s, post what you find, in going from the RE series to the UE series, DDs to BAs? I would be very interested to know how you enjoy them compared to the RE0 that you have now,
oh and if you decide on getting a ZO! which is utterly freakingfantastic btw, wait until they work out the kinks, V2.3 or so, so you get the full effect of what it has to offer,
and when I had my 262s, using the large bi-flange tips really helped out with the bass end alot! in fact I use the lbf tips with the 600s, and I will probably do so for any other IEMs I wind up using, they are very nice! with opening up the sound, any other tips that I've tried seem to muddy up what I 'm hearing? go figure,
anywho, happy listening, ho ho ho!