I have watched two episodes of this on iPlayer so far and think that it is very good. The second programme had plenty of birds in it and I enjoyed seeing the underground Wheatear nests. It is pleasantly low budget with (I assume) just Iolo, a camera operator and a sound recorder, which makes it feel a lot more intimate. I look forward to working my way through the remaining episodes.
Just finished watching this and found myself disappointed there were only 4 episodes, so it must have been good! On Springwatch etal I usually find Iolo a bit dry and stuck to a script he's not that keen on, whereas on this he felt a lot more natural and spontaneous with what he was watching, much better. BBC - give him some more series and it doesnt have to be just Wales!! (disclaimer - nothing wrong with Wales!!).