Took the Sojourner out for a few test runs, ran it against similarly-BV'd Clan 'Mechs.
The Prime is pretty decent, though as with a lot of designs I wish it had a second ton of Plasma ammo.
The A, against all expectations, was pretty fun. Very accurate with its firepower, probably good at taking out lighter or more maneuverable 'Mechs. Cheap in BV so easier to field, don't really case about the Micros 'cause it's just a ton and they're good back-up crit-seekers if the RAC/2 jams. Just wish a third ton of PAC ammo had been scrounged up.
I can see the B having a small niche, but it got absolutely mauled by the Guillotine IIC it went up against. Not a config I'm a fan of, pretty pricey in BV for the damage it can put out.
The C is a nice fire support variant. Like the deep bins and it has enough sinks to bring the HLL into play in more of a direct combat role. Works well.
The D is a variant I really want to like, but it kept getting its right arm torn off before anything else, leaving it mostly neutered.
All in all, pretty interesting 'Mech. Bit fragile for a "tough" 'Mech; the 20 points of armor on the torsos or arms really gets stripped fast in Clan warfare, and the Sojourner ain't fast enough to keep the TMMs high to avoid that. Its probably a 'Mech that works best at bullying lighter or more fragile 'Mechs. I like it, though, it's interesting and I'm willing to forgive most of its faults because of that.
Was there compromise with the Sojourner? I was surprised to see that it had a inferior standard Heavy Large Lasers verses the Improved version. Resources needy?
Nothing said in the fluff about it. It does shave roughly 90 points off of its BV, and reduces the number of possible explosions on an already pretty explodish variant. I don't think it's a bad choice for what remains mostly a fire-support 'Mech.