Quick review.....
The blog chosen to post to was unrelated to my niche, but, it is a very high quality blog. The article written was a little off-topic too but I guess it had to be written to fit with the general content of the blog. The PR and DA were far higher than the minimum guaranteed. However, the link was worked in well and the content itself was very well written. The bottom line is though, that I am pleased with the outcome and have placed another order to see how that pans out.
It's a tricky one. I've ordered a similar service from a different provider and they wrote more relevant content and posted on an on-topic blog. However, the blog post was fairly crappy and the blog itself was very poor so I'd certainly choose article/blog quality over 100% topic match. I think if the keywords can be worked in naturally then it's not a problem.
Cheers.
Fat Dad