(Note that this review is based off of the TV show alone, and does not include the OVA)
Occasionally, whenever I watch a show, I'll wonder if the show has a function to serve aside from provide entertainment, and if so, what is that function (this isn't exclusive to anime - I've wondered this while watching shows like Numb3rs and Burn Notice)? Even if I'm watching an anime based off of a manga, I still will have this question every now and then. Pilot Candidate was a show that I found myself asking this question.
The story is somewhat standard for a mecha show - Humanity is under attack from an alien race (called the Victim in this show - insert Tumblr joke here), they've been cornered into one last bastion, and their main defense are giant robots. However, there's a slight twist here - it focuses on the training program for the pilots - a "Pilot Candidate" system. This is actually somewhat unique, as I can't think of another show that does this - most of the time, the main character either "falls into the cockpit", or pretty much starts off piloting the mecha (Gundam SEED is an example of the former, and Gundam 00 would be an example of the latter). This, combined with the cast of characters (who I'll talk about in a second) and some of the plot threads that were introduced (but never resolved, as this show was canceled in Japan before it finished airing) leads me to believe that this show was supposed to act as a somewhat more child-friendly version of NGE. The plot was one that was suited for 24 episodes instead of 12 - it would have worked better if they had planned on having the first season consisting of 12 episodes cover the graduation of the class, and then have the second season (if it came into existance) focus on the struggle against the victim.
The art on itself is somewhat similar to the style from Martian Successor Nadesico, and while Nadesico's art style was fine for the time it came out, it's out of date in Pilot Candidate's case. Also, I find the fact that Xebec chose to animate the mechas using CGI to be a rather baffling one, considering the fact that I can't think of any other mecha anime they've made where they used CGI to animate the mechas - they drew the mechas by hand in Nadesico (which aired before Pilot Candidate), and Fafner of the Blue Sky (which was also made by Xebec, and aired after Pilot Candidate) featured hand-drawn mechas as well (while the aliens in Fafner were made using CGI, this was done to make the aliens appear more...well, alien in contrast to the surroundings). Heck, I've heard people call the CGI used in Blue Submarine No 6 (which I haven't seen as of writing this) better - and that show was by Gonzo, who are infamous for bad CGI.
The music is actually really great - it's basically something that sounds like it's from an epic sci-fi movie in the same vein as Star Wars.
The dub, on the other hand...not so much. While this isn't the worst dub I've heard (I've seen the dubs for Garzey's Wing - which is worse than Pilot Candidate in terms of dialogue - and Love Hina - which is worse than Pilot Candidate in terms of the voice acting), it's a really bad one - although it's definitely one that you can make fun of (so if you want to watch this show to have a laugh, I recommend the dub for maximum enjoyment). In fact, the existence of a dub for this show baffles me, mainly because, as previously mentioned, this show was canceled before it finished airing in Japan - while Deadman Wonderland also suffered this fate, that show actually got a good dub (and that's probably part of the reason why it enjoyed so much success in the U.S.).
Most of the characters are pretty stereotypical - if you've seen most mecha shows, you can probably fill in the blanks regarding most of the characters (the mentor is a grizzled old vet, the love interest is a tsundere, one of the best friends is a know-it-all, the rival is an emo kid, etc). The only one that's really of note is the main character - mainly because he's like a very excitable combination of Ash Ketchum and Kira Yamato, except he has none of the redeemable factors of either character.
The only reason I actually watched this was because of the fact that Adult Swim has never aired this series a second time - in fact, they supposedly took out a banner saying that they would never air the series again. And if that doesn't give you an idea of how bad this series is, consider this: the anime was one of the main factors that killed off the manga.
I guess if you watched the series as a kid, it's worth watching again just to see how much it aged. But if you didn't grow up watching it, then you're not missing out on anything if you choose to skip this.
Alternative recommendations: Gundam SEED, Nadesico, Fafner, Vandread