I personally found this to be an easy choice, although the comparisons are still worth it to truly justify my decision.
For all of you who'll treat this as another tl;dr post, I'll tell you straight up that my vote is for Castle Seige. If you feel like reading, then be my guest.
First of all, I'm going to cover the most basic part of this discussion: Layout and Legality. Now, Final Destination has a very basic layout. It's simply a gigantic flat surface, with a somewhat jagged appearance on the bottom. Castle Siege has 4 different "stages". The first is a small structure with a slight elevation on one end, and a platform on each side. There is nothing under the stage. The second part of the stage is a large area with 2 large diagonal platforms that lead past the stage limits. There are also other platforms, some of which are held up by destructible statues. Both sides of the stage are walk-off edges. The third part of the stage is a medium-large, mostly flat platform. It tilts back and forth. The fourth part of the stage is the transition stage, which appears in between the changes of each stage. This stage has no platforms, no walls, nothing. Just an invisible floor, and two walk-off edges. This stage only appearsfor a few seconds before another part of the stage appears. Now, concerning legality, FD is the third-most neutral stage, behind Battlefield and Smashville. This is because there is nothing very negativeabout the stage. The two main elements that make it slightly than the other two I mentioned are its size, and its ledges. Because of the size of the stage, characters with good projectiles naturally perform well on this stage. Also, the ledges are awkwardly designed, which causes problems with some characters recoveries. Besides those two factors, the stage is very much neutral. Castle Siege has some legality issues, which prevent it from truly being a neutral stage. There is virtually nothing wrong with the first part of the stage. The blockade in the center may hamper gliding recoveries, but those characters have little to no problem getting back to the stage (except for MAYBE Pit.) The second and fourth parts of the stage have issues, because walk-off edges are just screaming for chain-grabbers. The third part of the stage is actually a pretty balanced stage, and I don't mean that literally. XD The ledges can cause havoc to those unprepared, but the rocking of the stage, combined with the rise on one half, makes it so certain projectile spammers will have a harder time with the spamming. Overall, in terms of Design, CS wins, simply by being a more complex and appealing stage. In terms of Legality, FD wins.
Next is Artistic Value. Honestly, I had to think about this one for a bit. CS has the statues, and lava, and other castle-like factors which truly make the stage appealing. FD is a very vibrant stage. The platform has a very intense look to it. The backgrounds are incredible. They really make you feel like you're rushing through time and space. In this category, it's a definite tie.
This last section is more opinionated than anything. I call this one the Fun Factor. For FD, there is nothing to screw you over on top of the stage, but trying to recover is annoying. I give the Fun Factor category to CS though, because there's more to do, even if the walk-offs screw you over. At least you can screw someone else over in return, and that's very fun. With the stage consistently changing, and having to use multiple ways to survive/kill overall, it's truly the stage that keeps you going. It really keeps you thinking.
My ratio for this "match" would be 55:45 Castle Siege. The Fun Factor just allowed it to beat out FD. Very close, though.
There you go. To think, I could do this everyday. :O
:D
P.S.: There's one other factor I forgot about until a minute ago: Music. FD's music generally revolves around the main theme, but does have its own little flare. CS's music is orchestrated masterfully. I enjoy every track it has to offer, even Melee's guitar version of "We Ride Together". At least, I think that's what it's called.
Well, after thinking of the music, I'm changing the ratio to 60:40 in Castle Siege's favour.
P.P.S.: I need new batteries for my Wiimote. Maybe I should consider just buying a rechargeable pack. Yeah, I'll just do that.
