So this could be several things. I get really bad bite or just a ... chemistry disagreement from all things MacBaren and Sutliff that I've encountered. I think the two are related as well(someone correct me if I'm wrong). There's the phenomenon of tongue bite, which could be heat combined with moisture, and then sometimes it also colludes with the third possibility-- baccy "juice". If you've ever had a smoke get wet enough that you suck a droplet of tobacco juice onto your tongue, you'll know that it can be very 'spicy' and tingly. Whether its additives or tobacco juice or hot steam or a combination is hard to say, but I think if you reduce as many of these variables as possible you'll have a better experience. Smoke tobacco which agrees with you, smoke slower, pack carefully, run a cleaner down when you notice moisture. These 4 things combined will minimize these unpleasant sensations.
I'm a big cob smoker I suppose out of necessity even though I do like the pipe itself. If I had unlimited funds I
suspect I would mostly smoke briars simply for one reason: The bottom of the bowl. Cobs have one true flaw for me in that they have the wooden insert, which gives you an acrid burning taste when the cherry reaches the non-cob parts of the cob. I wish MM made cobs with the cheapest scrap briar inserts and charged a few bucks more, that'd be the dream for me. I personally put very low value on aesthetics(partly due to necessity as well), but for people where how a pipe looks, they generally prefer briar which can show off artisan elements. Cobs are mostly.... corn, wood, and plastic. :D
Purely personal preference. There's something to be said for the fact that most bulk aromatic mass-produced pipe tobacco will be lower quality tobacco, it can't be high quality tobacco and be mass produced, there's just not enough creme de la creme leaf out there to make
that much whiskey cavendish, heh. But I'm sure there are blends that are identical to the high quality tin contents out there. The main value of the tin is that it's hermetically sealed(hopefully-- tins have been known to leak sometimes for various reasons), which is great for aging.
I can't offer much here since I've never had bookshop personally, dying to try it-- but as a fan of runny french style cheese, one man's bad cheese smell is another man's good cheese smell.