I did like the text messages nearly all the time; I thought the triple use in the first instance was over-egging it (twice would have worked better).

I was so relieved that Mycroft was only Mycroft (unless that's a twist) that I didn't mind very much. I have a bugbear about one-or-two-off characters becoming ubiquitous in fanfiction* (eg Avalon); it may seem inconsistent when my rare excursions into fanfic have a bias to one-off characters, but I like to see them not interacting with regulars (ie a story about Avalon and her own gang would be fine).

It may also be inconsistent to be happy about Mycroft being Mycroft, but I don't think he's been over-used in the way that Moriarty and Adler have.

* Which this clearly is.