I rated this three stars – I'll tell you why.
In so many people's minds, especially those who grew up with the old series, Tom Baker was the Doctor. He was the longest serving, and most recognizable of them all. Keeper of Traken and Logopolis are his last two episodes. As is mentioned in the special features of these discs, there was a new production team that wanted to take the show in a new direction, and that meant replacing Tom Baker, who by his own testimony, was hard to work with. But all they knew is that they wanted change – they had no idea what to replace him with.
The TARDIS starts with the Doctor and one companion, and ends up with three companions by the end of the three serials. It got crowded, with too much reference to anything but a plotline. Also, the evergreen (and black in this case) Master returns, and steals a body (Anthony Ainley) in which he appears for the best part of the next 8 years of Doctor Who serials.
New Doctor, new staff, new companions, new Master – but directionless. The storyline in Castrovalva is OK, but the special effects are enough to make you cringe. (That goes for all three serials).
The more I watch it, the better it gets, but I make you no promises.