"John is great," Stamos' costar Lori Loughlin told PEOPLE at Hallmark Channel's lavish dinner during the Television Critics Association's summer press tour.
The actress was pleased to see her television husband, 51, in fine form since he completed a rehab program following a DUI arrest June 12.
"I've been with him all day at work," Loughlin, 51, said. "He's really doing well. He's happy. He's productive. He feels good, and it's nice to see him on his feet and doing well."
Candace Cameron-Bure, who plays D.J. Tanner in Fuller House, agreed.
"John's awesome," the 39-year-old told PEOPLE. "He's fantastic, and we're all just having a blast together. And it's hard to describe. It's just so many laughs."
Even prior to the cast reassembling for the rebooted sitcom, Loughlin said she's remained in close communication with her longtime friend since the first series ended after eight seasons in 1995.
"I'm always in touch with John," the When Calls the Heart star said. "We have many good moments, and he's just great – I mean, he's one of the greatest guys I've ever met. He's got such a good heart. He's so giving. He's so smart. He's just a dream. He's doing well, and I'm happy for him and happy to be with him this week. I'm happy that we're all together."
Even more returns are on the way, including Blake and Dylan Tuomy-Wilhoit, who played Jesse and Becky's twin sons Nicky and Alex on the original series.
"They're back, yeah!" Loughlin confirmed.
And although some fans feared that D.J.'s teen-years boyfriend Steve Hale, played by Scott Weinger, might actually be her now-deceased husband in the sequel, Cameron-Bure offered reassurance, noting Weinger will also join the reunion: "Steve is not dead, so fans rejoice," she said, chuckling.