I have an Evo2i and recently auditioned an S300i and Pre3/A1000 setups.
The Pre3/A1000 was heard whilst on holiday in Singapore, and as it had a rather more reasonable price tag on it, was seriously considering.
The Pre3/A1000 has a very similar presentation to the S300i, but is simply better in every way.
I then heard the S300i vs my own Evo2i. My opinion is that the S300i was brilliant in "hi-fi" terms, yet somehow lost the plot from the point of view of involvement in the music. To quote a Linn user, the Evo was simply more toe tappingly fun. Can't explain why, but I couldn't get excited about the S300i.
So I'll be keeping the Evo2i, which is fine as it also saves me some dosh for an even better front end.