Edit 30/05/2012: i sent rainbow an e-mail to ask what she has. here's the e-mail:
Hello people from Rainbow,
I have a question about roxy in season 4 of winx club: Which transformation does she have?
Many people wonder if roxy has: Believix (complete/incomplete) or Magix Winx (Charmix in Nick) but then with bigger wings because al the earth fairies have big wings.
So wich one is it?
Thank you for reading/listening,
Sincerely,
DDRWinxFan (i used my real name but i'm not gonna tell that here XD)

Does anyone get what transformation roxy has? i think it is the magic winx (charmix in nick) and then you ask why does she have those big wings then well because all the earth fairies have big wings. so what do you think? post it here.

I'll have to watch season 4 from the Nick dub to answer this (because I haven't watched season 4 yet, due to lack of acting skills in the rai version), but from what I know it's a charmix transformation but she looks different because of her heritage as an earth fairy, earth fairies have different transformation features which is why I think she looks different from the Winx.
And plus on the show she didn't have that many spells or attack to use, and that could possibly be because she is only on the charmix level.
If she was a believix fairy, she surely would have got her Sophix and Lovix powers. That's my theory.

What i think is that either:
her Believix is incomplete, therefore cannot get Lovix, Sophix or her other wings
or that she has Magic Winx only with bigger wings because she is an earth fairy
but hopefully Nick will clear Season 4 up a bit

I think she has Charmix.
Because fairies usually believe in themselves in order to transform.
Like how Bloom transformed in season 1 ep 3.

It's not opinion, The rai english voices were just bad. It really was bad.
The only problem I had with Rai was the voices everything else I loved.

i grew up with 4kids and it will always be my number one
i hate the Rai voices for season 1 and 2, but 3 and 4 aren't as bad
i can't stand Rai in season 1 or 2, i just can't watch it.
i know that 4kids cut out and changed so much but its still my favourite
in order it goes:
1. 4kids
2. Nick
3. Rai (closely behind)
thats my opinion anyway

I don't like 4kids voices. I like RAI and Nick, but i can't watch 4kids.

I think Roxy transformation is first transformation. I think it's like nick transformation charmix.