I bought myself a bottle about 3 weeks ago, my first ever TSW Bourbon Cask. Enjoyed it, but were a little disappointed due the lack of peat. I must say however, it does compete very well with middle to top shelve bourbon finished unpeated blended Scotch whiskies. Three Ships blended whiskies is blend of SA and Scottish malt and grain whiskies btw, and this shows in the taste.
To answer your first question, no, it does not taste like Bourbon. One must first understand what makes Bourbon unique. Bourbon is matured in virgin charred oak barrels, this is what gives Bourbon its unique taste apart the mash bill and distillation process used. These barrels can only be used once for Bourbon, so these barrels are sold to whisky makers around the world to be reused.
TSW Bourbon cask is whisky that was matured in a barrel like this. This is where the bourbon notes come from. One must understand that the notes are very subtile and as not in-your-face as a true Bourbon.
Although Bains might taste like a Bourbon, it still lacks the notes that one would get from a virgin charred oak barrel, although the mashbill and distillation process is basically the same. Harrier on the other hand is a cheap way to get a top end babalas, at least, that is my experience, lol.
Depending on what type of TSW you like, you will be pleasantly surpriced or feel a bit disappointed. Don't get me wrong, this is a really good whisky, but if you are looking for peat, you are going to feel a bit disappointed. It is however miles better than the standard 3yo whisky, and Harrier for that matter, I still can't get around that hard green pear note in it.
Also, as you know, Bains is not TSW, although Bains makes up a percentage the TSW blend. If you are going to look for a Bains-like taste in the TSW Bourbon cask, you are going to be disappointed. As I said previously, this is more like a Scotch blended whisky with some bourbon notes