I purchased the Speedy 30 Idylle in Fusain (dark brown) colour back in April of 2010 (for $1080USD, and the price has now gone up to $1300USD), and I have probably used it about 15-20 times since then...I'm very careful about bringing any of my nice bags out depending on where I'm going, and what I'm doing.
From my experience, I can say that my Idylle has held up quite well- no pilling, no discolouration, etc. But this is also largely due to the fact that it is dark brown colour, both the fabric of the body, and the leather of the handles. I kept this in mind when deciding whether to get the classic Speedy (with the light tan coloured handles) or the Idylle.
In my opinion, if you are wanting to get a Speedy to add to your collection as part of a classic, timeless piece, then you should choose the Speedy 30 from the Idylle line. 1) The bag now comes with a shoulder strap, 2) The handles are dark brown, which will never discolour with time, like the classic light tan coloured handles from the classic Speedies, 3) The fabric from the Idylle line has added reinforcement from an additional coating which the previous (but similar) Mini Lin line did not have, 4) You will have a more unique-looking (but still classic) Speedy 30, 5) The Fusain colour (dark brown fabric) looks really great in contrast to the gold hardware.