Theis here, and we've given you our first impressions, but what of yours? A phone's success is ultimately dictated by how many of you are prepared to fork out for it. If consumers no likey, then hard luck young squire, but never shall you joust your way to sales success in this realm.
Let's see what you had to say on Facebook and in the comments.
Too big, too plasticky
Many of you think the S4 is too large, and were disappointed to find that it's made of plastic, just like its predecessor. "If plastic phones is your thing then it's great," said Howard F Smith Jr, with Muhammad Omair Tanveer adding, "Plastic? Please no."
Late8 agreed, saying, "Design is still dull, plasticky and cheap looking. Come on guys this is a £400++ phone and it looks like a Fisher-Price toy again!"
Doesn't improve enough on the S3
Many of you thought the S4 didn't offer anything particularly impressive enough to jack in your Galaxy S3s.
"Nothing making me want to switch from the S3," said Matt Dualor Chambers. Kieran Sampson agreed, saying, "I am currently using a GS3 and I don't feel that the GS4 adds enough (for me) to warrant getting an S4."
Feeling underwhelmed and disgruntled was certainly a theme among Samsung fans. "We, loyal Samsung lovers, have been betrayed by Samsung! The worst phone of 2013," opined a crestfallen Rohaan Manzoor.
"I feel there is something missing from this device and I am not sure what. This time last year when the SIII was announced I couldn't wait to buy it and it was the same with the Note II," said iam a wp7 (who would also like to change his username -- sorry about that, duder).
Juliet Purcell saw the S4 launch as an opportunity, however, saying, "Maybe when the S4 comes out I'll be able to afford an S3!!", Juliet.
Not a worthy rival to other Androids
Others of you thought the S4 wasn't a worthy a rival to existing Android phones. "I'd rather save £300+ and buy the Nexus 4," said Pete Sherriff.
"Sony and HTC release solid builds. I've been all Samsung until now. Not anymore..." was Paul Bedford's contribution. "wipes the floor with it," said Alan Goodwin.
"This has to be one of the most underwhelming phone releases ever. After seeing the stunning new offering from HTC last month I was waiting for this to be released to make up my mind what to buy but nothing about the design of this phone screams premium," said commenter amazontreefrog.
A little love for the S4
Not all of you were being negative Nellies though -- there was also plenty of enthusiasm and excitement to be found. In our Facebook poll, more of you thought it was ace than were disappointed by it.
"I was hoping for a new design, but now I'm glad they've stuck with the known formula and just polished it. Other than that it looks to be a great phone!" said Paweł Leszczyński, with Crispin Norman declaring it "an awesome piece of innovation! Apple have been eaten alive tonight by the Galaxy S4!!!!!"
What do you think of the S4? Hit play on our hands-on preview below, and let me know in the comments or over on our Facebook page.