The Magician's Oath, by Scott Handcock, is set at about the same period as Paul Magrs' novel Verdigris which I was reading at about the same time. Mike Yates tells the story of a magician who is sucking up all of London's energy. The plot is nothing terribly new; Richard Franklin does the voices adequately, as does Michael Chance playing the evil magician. Verdigris is better.
George Litefoot and Henry Gordon Jago are not technically companions, and there is almost no trace of the Doctor, but Andy Lane's The Mahogany Murderers is totally brilliant: the Victorian pastiche which he did so well in All-Consuming Fire, combined with the wonderful return of Christopher Benjamin and Trevor Baxter (who apparently hadn't seen each other since 1977) delivering a beautiful product. Even if for some peculiar reason you haven't seen The Talons of Weng-Chiang, you will enjoy this; if you do know the older story, you'll love the sequel.
The same, alas, cannot be said for Nigel Robinson's The Stealers from Saiph, in which Mary Tamm going solo does a decently professional job of a rather lousy script involving alien goings-on in Antibes in 1929.
David Bishop's Enemy of the Daleks came close to being an interesting story of the Seventh Doctor being manipulative with the time stream again (and trying to shield his companions), with some surprisingly good good John-Foxon-tries-to-be-Keff-McCullough music. Unfortunately it is badly let down by two terrible performances from the guest cast - Kate Ashfield and Bindya Solanki, who are both fairly well known actors but utterly fail to convince here as the officer and sergeant in charge of fighting off the Daleks. (Solanki is slightly better in the scenes on her own without Ashfield, but this is not saying much.) BF occasionally gets an under par performance (indeed, more often than not the regulars are the ones to blame) but it's rare to have two of them in the one play.
Paul Sutton sometimes bites off a bit more than he can chew, and I think this happened in The Angel of Scutari: it's a nice idea to have a fragmented plot, presented out of order, but Big Finish has done this before and better (most successfully with Creatures of Beauty). It seems also like an attempt to give Hex some character development, presumably in order to get rid of him some time next year, but ends up with Philip Olivier doing a one-note nursing whine while waiting for Florence Nightingale, while the Doctor and Ace shift rather confusingly between British and Russian captivity. The cast admit to their bafflement in the CD extras, and one can sympathise.
Those two CD sets / downloads also feature the second and third episodes of the ongoing arc of The Three Companions, by Marc Platt, concentrating on Polly's reminiscences of a Two/Ben/Jamie adventure. The second episode was a bit dull in getting them all together on the planet where Something is Going to Happen; but in the third episode the Something actually Happens and it all seems to come together well.
Wirrn Dawn, written as well as directed by Nicholas Briggs, is OK but not spectacular, with the giant insects returning to torment Eight and Lucie, and also a rather colonial relationship between two human cultures. Actually I thought BF missed a trick here: most of the guest cast (Colin Salmon, Daniel Anthony, Liz Sutherland) are PoC, and we could have had a more thoughtful exploration of colonialism than we got.
With The Scapegoat, Pat Mills writes the second WW2 audio this year (the first being Steve Lyons' Resistance). This is occupied Paris, but not as we know it; I kept on thinking of the line from Douglas Adams about the enormous mutant star goat, whose smaller cousins are running a theatre near the Moulin Rouge where the Doctor and Lucie find themselves performing. I listened to it twice and am not sure I quite understood it but I enjoyed it.
I was very unimpressed with Jonathan Morris' The Cannibalists at first: as I have repeatedly said, I hate cute anthropomorphic robots and this seemed to be just a story of the Doctor and Lucie saving the nice robots from the nasty ones, enlivened by Phil Jupitus' performance as the nicest of the nice ones. But there is a brilliant twist at the end which made me very glad I had stuck it out.
The season finale, by Eddie Robson, takes Lucie and the Doctor to near-future London where I have to admit that I was pleased and delighted by the revelation at the end of the first part of who the baddies actually were (though the titles of the plays, The Eight Truths and Worldwide Web contain pretty good clues). That was the best bit of it, unfortunately; yet another religious cult turns out to be brainwashing people for alien invasion, and the Doctor and Lucie spend a lot of time running around being imprisoned and attacked. Poor Stephen Moore, as the displaced cult leader, sounded more and more like Marvin as his lines got less and less interesting. I didn't hate it quite as much as steve_mollmann, but like him I was glad when it was over (finished it this morning while doing my Wii Fit routine so made sense to listen to the end).
So, of all of these, my only really strong recommendation goes to The Mahogany Murderers, which is also rather oddly the only one of the stories without an appearance from the Doctor or any of his companions. Most of the others can be skipped