"I am not exactly sure if this one has active noise cancelling. Could someone confirm?"

I doubt it...
But it's not as necessary with such an "in-ear" style as it is with for e.g. the MM 100.
Tis not even necessary for the MM 100 if you're exercising in relatively quiet areas.

Sorry been away for a week... I ended-up getting the MM 100…
I couldn’t find a huge amount of negative commentary in-terms of ingression killing it prematurely.
There is a bit about it being uncomfortable, but so far it's been great in that area for me.
It does pinch one of my ears a tiny bit, but I'm getting used to it.

It’s substantially more $ than the BH-505, but I found a retailer who’s had some in-stock for ages, and wanted to move it.
Best price in Oz was about $200, but they sold it to me for $154.
Still pricier than the cheapest 505 I found ($69), but hugely less than MM100′s official RRP here.

No idea how it compares to others all up, but I doubt SQ will be worse.
If it’s compatible with the APT-X BT codec adapters, then all the better.
But I think they may only be for higher-end BT Senns though.

So far no malfunction with sweat, early days though, only been on three big runs, no idea how good the mic is, will rarely use it.
The SQ is exceptional IMO, as far a standard BT is concerned anyway.
I've had one situation where the paring has broken mid-run for some reason, but it's easy enough to resync.

I decided to not use use it with my N900, I think the iTouch 4G is better suited as my DAP (among other things).
I will keep my N900 focussed on other tasks/jobs....

Hope that helps.

Solved choppiness by putting N900 into my coat pocket instead of trouser/jean pocket Practicality beats purity!

I've had no choppiness with my MM 100's...
But when I go running I normally have my iTouch in my hand or my armband.

Motorokr S305. Although the S7HD does seem interesting in that it uses flexible wiring instead of the stiff band of the S305. If you don't mind IEM's reducing outside noise (for those neighborhoods full of dogs, etc) and no volume/playback controls aside from play/pause, consider the HBH-IS800.

^ Of those three, the model whose reviews hold-up at Amazon to a respectable 4-stars despite hundreds more than the other two, is the S305.
But there is this telling review & subsequent forum banter, which highlights why the MM 100 is better, if you can find it for a bargain like it did

Same user's actual MM 100 review....
http://www.amazon.com/review/R258N18...wasThisHelpful
Two main Amazon sites reviewing MM 100, very low ratio of 3-star or less (negative) reviews
http://www.amazon.co.uk/product-revi...DateDescending
http://www.amazon.com/Sennheiser-Blu...DateDescending

I'm the OP and I've outlined the complete rationale for my decision, mainly in my OP, but thanks for your thoughts!