I would probably get DCT but for a true manual inclined buyer, 6-MT should be even better F10 than E60 and here is why.
1. MT is offered now from the start of production so M spent the time to get proper gear ratios right and not some frankenstein gearbox rammed into the car after customer complaints.
2. .10 difference according to M between 7-DCT and 6-MT 0-60 plus 24mpg. The gearing probably makes the 6-MT closer to 7-DCT performance compared to E60 with a good driver.
3. From pics, short and slick shifter just like 1M.
4. Tons of Tq down low makes driving 6-MT in S63Tu easier and much easier than manic S85 in E60. You will most likely shift gears less since there will be Tq all over the rev band. If you ever owned E39, it should be like that but with much more more power
5. We need a test guinea pig for some of us waiting for MY2014. Sorry