hee hee... this question is harder to answer than the A-Level Physics & F-Maths "S" paper.... though I have not taken or seen them before... :bsmilie:
Any suggestions that I give, will definitely attract alot of flame... coming from someone who shoots film most of the time, this is how I feel....
The D700 & M8 are two different beast. Depending on what you are going for, high ISO, low noise, nothing beats D700 & 5DMkII today. With M8, anything above ISO640 is only good for B&W.
At base ISO 160, and with a good glass, the M8 performs like a gem. A professional photographer, who shoots concerts with the M8 told me this. The resolving power of my Voigtlander glass with the M8 sensor outperforms his 1DMkIIn with his best L lenses. He earns a living shooting concerts and he owns quite a number of the L glasses. He uses the M8 with my CV lenses. And he told me, the CV lenses are best value for money lenses he has come across.
Generally the RF design is better than the SLR as it does not have a mirror box, the rear lens sits closer to the sensor, hence image quality naturally is better. However, this statement is not 100% true as with the modern technology advancement, sensors on DSLR improve much quicker than Leica can come up with firmware upgrade. And depending on what & how you shoot, on sime situations, RF just couldn't do the job as well as a DSLR.
Hence, to answer your question, "Is it a steal? Is it worth it?"
1. If you really like RF, for it's size, handling, nostalgic look, M8 is the only digital body with the largest sensor that you can get new today. At $5700 (with Summarit 35/f2.5) is it worth it? Well, a few months ago, the same set would cost you $7200 at Alan Photo. Maybe it will cost $5000 in 6 months time.... and $4000 in 1 year time... and $2800 in 2 years time!!! Some how digital cameras follow Moore's law
2. Personally, I hate to bring large cameras around... As I prefer to walk on foot, anything more than 2kg in my camera bag will affect my mood for the day. A D700 + 17~35/f2.8 or 24~70 weighs about 3kg I think... (someone can correct me on this) + a lowepro flipside 400 or Compu Trekker AW, with flash or 1 or 2 prime glasses + cards + blower + HardDisk picture viewer... easily can come up to 7 to 8kg or even 10kg. Think again if you are going to cover 10km on foot to capture moments with a 10kg backpack. (like carrying a sack of 10kg rice from NTUC Fairprice walking back home) :bsmilie:
To summarize, if you would be using the M8 extensively after you've bought it, then it will definitely be worth every cent that you pay for it....
But if you are someone like me... only do serious shooting during holidays, and that only happens one or two times a year only.... I guess, it's not difficult to guess what my advise will be.