Review:
I ordered the small package for one MNS of mine. Got the report in about two weeks after ordering. There was little problem with some links they built for me, but it was addressed quickly and solved.
As to the result: About eight months before, this site of mine was sitting at 31st position in the SERPs. Back then, I used one guest post service on BHW, and the site completely tanked and never appeared in Google search results top 100 again. Meanwhile, when I checked, all of these guest posts I ordered went dead...
So I decided to use this service of BigBuddy, just to see what it can do, after all it costs nothing. Now, the site is back in SERPs, on 28th position for main KW. Ranking in top 30 for some other KWs too. We talk about low competition keywords here, just to clarify.
Opinion: I would say this is a good and safe type of links and the provider is very serious. It can be a good part of overall LB strategy for any kind of competition level and I would definitely recommend it. However, I would not expect any magical results from it even for LCKW, and you should not rely on it solely.
Hope my review helps.