Two points.
First, the neat thing about HGT is that it leverages parallalism. Namely, HGT only works is there are interesting genes you don't have - genes that evolved somewhere else, in a separate population, in a different evironment or niche, (and here's the important point) genes that evolved at the same time your genes were evolving. Take the last 4 billion years (plus or minus). If there was no HGT, then your DNA would be the end product of only four billion years of consecutive evolution. But with HGT, your DNA can effectively be the end result of tens of billions of years or more of concurrent evolution. HGT leverages parallelism!
Second, while I concur with the main thrust of the article(s) that HGT speeds up evolutiuon, I can't help but call attention to the implicit multi-cellular bias. The article implies two things I take excpetion to. First, that cells evolved over 3.3 billion years ago and then nothing of import occurred until multi-cellularity arrived on the scene. This is silly. I would argue that much occurred during that space of time within the context of single celledness - inventions no less amazing and complex than the more recent and visible multi-cellular inventions. Second, it is not at all clear that evolution as actually sped up since the dawn of multi-cellularity. Oh sure, there are a whole bunch of multi-cellular forms around that on the surface make it appear that the pace of evolution must have increased. Afterall, there are feet and wings and bills and brains where before there were none. But all those multi-cellular forms rely upon single cellular mechanisms of no less complexity. Any software developer will tell you that writing the code to loop a million times is trivial, perhaps a whole lot simpiler in fact than the code that's actually inside the loop.
My point is that as multi-cellular organisms, we may be biased towards viewing multi-cellular adaptations as somehow more complex than those less visible but no less important mechanisms which predated multicellularity at the single cell level. The recent so-called increased pace of evolution may simply be an illusion of our multicellular biased perspective.
