Some people, not everyone here, but some are too closeminded.
Wiichuck has some clear advantages over any other controller setup.
I used the GC remote since the day of Melee's release. I decided to switch to WiiChuck because i wanted to, and now I'll never go back.
First of all, Synching isn't that big of an issue, lol.
Second, you can customize it in a variety of ways to make it fit your style, although you can do this with the GC remote as well.
For example, my setup is:
A: Standard attacks
B: Specials
Down Dpad: Jump
Side/Up Dpad: smashes
Z: Shield
C: Grab
A+B: Don't remember lawl.
Tap Jump off
Shake smash on or off, depends on who I'm using.
Now, since I main Sonic, this is effective for me because it allows me to do anything I wanna do. Some of Sonics ATs are also made easier with this setup.
the main advantage of the WiiChuck over GC are:
1) Shielding. Quicker shielding overall. Even if you remove the springs, theres still more travel time on the GC remote.
2) Smashes. If you have smashes on the D-Pad or use shake smash, you don't have to move your finger from their general location to perform a smash attack, unlike the GC remote where your fingers are constantly flailing up and down between Cstick and ABXY.
3) Aerials. Basically the same idea as above. Especially useful if you need to put up a wall of aerials or need to switch between aerials and specials rapidly or something. Everything is exactly where you need it.
Shorthopping is ridiculously easy with it on Down Dpad by the way, just flick down on a corner of the down input.
DAC/Mortar slide is also very easily done with the WiiChuck. You can do it with shakesmash, but my preferred method is using smashes on the dpad. Simply flick your finger from the left input to the up input on the dpad, and you have a DAC. Learn the correct timing or "speed" of the flick for your respective char, and it becomes ridiculously easy to do.
So yea, most of these things are advantages in fractions of a second, but in terms of an entire match, these fractions add up.
Theres nothing wrong with staying with the GC if so you choose, but don't bash the WiiChuck without knowing its advantages and what its capable of.