I'll keep this brief since I think many people feel the same way I do about some of the points below.
I liked both MC's and their relationship in the beginning, but I never cared enough about them to root for their HEA. There was nothing glaringly wrong with them but there was nothing special either. I enjoyed the first half of the book much more than the second half.
There were two major problems for me:
1. Haley. She was a little miss know-it-all that annoyed me from the first time she opened her mouth. Not only was she unbelievably pushy but she also insinuated herself in Roe's life every chance she got. It got to the point where I didn't even believe it was Roe's life anymore. I wasn't even sure if he could make any decisions on his own. Haley took over Roe's life and he let her. In my eyes he lost his individuality.
2. The Sapfest. I enjoy a sweet story IF it fits the characters, IF it's not OTT, and IF it feels like a natural progression in the characters and/or story. This wasn't the case for me in this book. The last third of the book turned too sugary for my taste. Their HEA felt rushed and not truly theirs. Haley's presence and what she did at the end threw their story completely off track. It didn't make sense and more importantly it doesn't fit who the characters are.
So far none of Cullinan's books has come close to Special Delivery.