Saw the matinee today (7/3). As someone who enjoys "old" SpongeBob (1999-2002 ish), but isn't a huge fan of what SpongeBob has become, I was a little nervous about this show and that it would become a potty humor, slapsticky musical to match what the tv show has become. I am happy to say I absolutely adored this show.
First of all, the set is just amazing. I walked into the theater and felt like a little kid again. They've done an excellent job making you feel like you are in the SpongeBob universe; this will definitely have to transfer into a larger house if it moves to Broadway. I don't think it will be as successful on a smaller scale.
Ethan Slater is doing an amazing job as SpongeBob. He uses the cartoon as a base, but definitely makes it his own. His role is rather physical - I can only imagine how tired he must be after a 2 show day. Lilli Cooper as Sandy was wonderful. She's a vocal powerhouse. Gavin Lee was a delight as Squidward. His tap dance number is a show highlight. His costume slightly reminded me of Faarquad's for Shrek. I can only imagine the time it took to get used to tapping with four "legs" 
I'm not sure whether anything has changed over the course of the run - it closes in a week - but there are a few things that weren't as strong as others. The Krabs / Pearl song, "Daddy Knows Best", was a little "blah" amongst the other songs. Although Emmy Raver-Lampman belts her FACE off at the end of it, which was fabulous.
As others have said, the Patchy stuff gets old - I'm a fan of the show and understood the reference but still feel it isn't necessary.
There were a few mishaps today, particularly with the "boulders" that are supposed to swirl down from the side of the stage. The larger ball got stuck and they ended up just throwing a "backup" ball from backstage for SpongeBob to catch. One of the circular screens was also flickering during portions of the show. Cast handled everything like a champ, though!
Overall, if they market this correctly, this could do well on Broadway. Kids and adults alike seemed to really enjoy it, and I wish the cast and crew the best! It was a very fun show with some great tunes and a stellar cast. Very glad I got to see this in its out of town tryout!
Oh, and if anyone from the Oriental theater is reading this - good lord, please turn down the air conditioning in this theater! Everyone was freezing our butts off in there!!!!