I've only seen the first season so all thoughts herein are confined to that season.
OVERVIEW/REVIEW: Summerland not only stars Kay, it also stars Jesse McCartney (as her older brother), features Zac Efron (as her boyfriend/friend) as a recurring character, and guest stars Sara Paxton (as Jesse's girlfriend) for about 5 or 6 episodes. This is a remarkably talented cast of teen stars. Zac Efron and Sara Paxton have always been good in all of the previous projects I have seen them in, and they are good here as well. Sara Paxton plays a "bad seed" girl, which is completely contrary to her other roles and overall image, but she does it convicingly. Jesse McCartney, I have to say I was surprised by. I've always disliked his music, and from what I've seen of his live performances, I've never found him to exude much charm there. However, he is a very good actor, and he handles the angst of the character really well. Even though all they ever really give him to do is surf and screw up relationships. But he deals with the angst and sadness of the role really well. As to Kay Panabaker, well, I of course love her work. Her facial expressions and vocal inflections are impeccable as always; she handles the drama well, and her essential charm still shines through. She handles the sadness of the character really well, especially at the beginning of the show when she's having trouble coping with the death of her parents. Her "apology" to Suzanne at the end of the pilot was probably my favorite moment of the entire first season. But she also handles the happiness too, the giddiness of young love, very well. Kay continues to impress me more and more with every new project I see her in. The adult stars on the show are generally adequate, but don't seem to be anything special to me.
Unfortunately good acting can't make an otherwise mediocre show a classic. Plotting is a big problem with this show. The plots are all extremely cliched and predictable, and the show overall doesn't seem to be adding anything new to the landscape of teen television. Let's take one plot for an example. Sara gives Bradin (Jesse McCartney) a marijuana cigarette, and he accepts it, not wanting to seem uncool; however, he never plans to actually smoke it. He puts it in the front pocket of his backpack and then doesn't zip it up. If you can predict the resolution of this storyline: congratulations, you too could be a screenwriter on Summerland. In addition, a lot of the dialogue seems stilted and unrealistic.
The relationship between Ava and Johnny is supposed to be the centerpiece of the show, but it shows no development at all over the course of the season. Ava and Johnny used to date, and they both still like each other but they are scared to take the next step and ask each other out on a date. So they have many conversations with their other friends, have many deep, introspective moments, etc. throughout the course of the season, while everybody knows (except them!) that they are meant to be together. There's only so long the audience can take this before getting bored with it, and the show really strains the limit of how far it can go.
Overall, I found the adult based storylines to be mostly fairly boring and wish they had dedicated more time to the kid storylines. I liked the Jesse McCartney love triangle, no matter how cliched it was (Bradin + Callie 4ever). Most of it is probably my Kay Panabaker love, but the Nikki storylines were my favorite part. I liked her interactions with Zac Efron a lot and her relationship with Amber seemed to be the only believable human relationship on the show, to me at least. But the adults seem to get even more face time than the kids. I realize that in a show with such a large cast it's very difficult to allocate the time evenly and properly between the characters, but I really wish less of the allocation had been to Ava and Johnny, and more had been to Nikki, Cameron, and Amber.
THE OFFICIAL OPINION OF THE TCR: A great cast, particularly a great teen cast, turn an otherwise mediocre show into a...well not good, but certainly watchable show. It's entertaining in the way that a drama is entertaining when you get to "know" the characters and who they are. Nothing special about it, I wouldn't be sad if I never saw another episode, and I'm not at all upset that it was cancelled, but it's certainly the type of show I could see myself being a regular viewer of if it had no other great shows in a competing time slot. 6/10.