He's very good, especially (and this is meant in a good way) for someone who has little or no opportunity to speak with Irish speakers (as far as I know).
Tánn tú ró-fhial liom!
An mhalairt ar fhad atá fíor.
BTW, I think you are best off to learn the standard initially at least. Once you know the spelling of the standard, you can start to pronounce it like the dialects, but as most formal Irish is written in the standard, you really have to know that.
I learned standard spelling and dialect pronunciation at the same time. It's not intrinsically more difficult than for any other language, since normative pronunciation and standard spelling are never a perfect match. There's always some
amount of diglossia.
I agree totally. I am glad I learned standard spelling and pronunciation initially (and I sort of have to use that for exams), because it gives you a good foundation to pick a dialect. I am a fan of standarised spelling for Irish, because pronunciation doesn't have to be the same.
I would also suggest that you don't start learning Irish by launching into the declensions because for a while at least, because if you are not used to initial consonant mutations and all the different ways that Irish nouns change, it is quite intimidating.
Fortunately, Ó Siadhail holds off for a bit before getting into that kind of nitty-gritty. IIRC, the Connacht dialect he teaches makes less use of the genitive than some others, which no doubt helps.
That's good. I only learned the declensions pretty recently, and I'm glad. Because now I pretty much know how to form the plurals when I hear the word, and I can figure out what declension most nouns are in because I know most of the genitives from hearing them. It's a great help.
Have you started learning ILuvEire or Seán or both?