I think the decision to have no two parters this year has backfired badly. 45 minutes is too short a time to develop characters other than the leads and everything feels a bit rushed. Storylines are thin as you cannot build any complexity in that time frame. It is also difficult to build tension.
These episodes are equivalent to the filler stories during the Davidson era, two parters such as Black Orchid and The Kings Demons. Writers such as Terrance Dicks used to hate six parters as they were too long and they had to effectively split the story into a 4 part segment and a two part segment (e.g. The Seeds of Doom, 2 parts in Antartica, 4 parts in the UK). No one was happy about the two parters, hence two three part stories in the McCoy seasons.
I think the best format is one story over 2, 45 minute episodes (the equivalent of the old 4 part story). This gives time for subplots, not too rushed a pace and more complicated storylines.