I have one, wouldnt call it a brick , closed its only just over 1cm taller than my old k750i.
Mp3 transfer is fine, i think its alittle slower than to the k750i but not a great deal.
my bluetooth is playin up at the moment so i cannot confirm tom tom compatability. other than that im happy with it, MP3 player is outstanding, it batters the k750i for clarity and volume ( i am using Kos in ear headphones on the mokia remote and they work fine also)
Off on holiday tomorrow with it so ill have plenty of time to fiddle about and check everything out.