That Boswell looks like a Jumbo; JM Boswell makes a fine pipe and has a niche market in big pieces. For comfort and affordability, I'd put his pipes up against anyone's. Particularly if you clench his wider stems distribute the weight of the pipes beautifully and his rustic style on his big pipes is immediately identifiable. Other makers -- notably Italian carvers, such as Mario Grandi, Ardor, Ser Jacopo and Radice -- make larger pipes regularly, perhaps because they have better access to briar. A local carver said that making bigger pipes is easier, which I can also understand.
Over time, my pipes have grown on me, and the first decent pipes I bought tend to gather dust in favor of the bigger bowls that form the core of my rotation, with a steadily growing collection of Ser Jacopo Maximas in particular. Part of the attraction comes from the way I smoke, which is somewhat fast and hard, which a big bowl helps, since the volume of the smoke is determined by the chamber diameter more than anything else, like a cigar's ring gauge (interestingly, cigars have also gotten bigger on average in the past few years; a cigar with a 60 ring gauge used to be almost unheard of, now everyone manufactures one. If I could smoke more regularly, I'd imagine I'd smoke smaller bowls or cigars throughout the day, though that might be a rationalization).
As LIPIPE stated, big pipes smoke longer and cooler generally. They're not for everything: I prefer a smaller bowl for flakes or stronger tobacco, such as Peterson's Irish Flake, but for a good ribbon with a substantial amount of Latakia, a large bowl works better for me. "Smaller" here has become relative; I frequent a pipe club here and I've noticed how a lot of guys -- particularly younger pipe smokers -- seem to favor pipes that I'd finish in a few minutes
Of course they take a little getting used to, but that's part of the hobby -- all pipes have their rhythm and take some breaking in. The largest of my pipes -- a Jumbo, a Bari Wiking and a Ser Jac double Maxima might draw some attention, but pipe smoking does in any case. Not that that's a bad thing.
Despite LIPIPE's warning, Boswell still seems to regularly post Jumbos on their site; I think their moratorium refers to their Grizzlies and Magnums mostly, which are even bigger and which are generally ordered as custom pieces and appear on their pipe gallery.