There is nothing wrong with the 150/2s which have been GWRd and have the Chapman seats with tables, they are pleasent enough to travel on all though the amount of legroom in certain seats is questionable. Especially the single seats opposite the toilet. I haven't been on one of the 150/2s with the Ashbourne seats, but have been on the 150/0s and don't find these as comfortable.
Unlike the 158s and 166s which we get most of the time now, they aren't tatty (If it's and unrefurbed 158 that is and have plenty of opening windows. These should be installed into the 158s and 166s for the frequent air con failures. On the other hand, when a 165 turns up with the Air cooling system, this is far better.