I have always been torn where the 1980s version of Red Sonja is concerned. I am a big Frank Thorne fan, but my earliest experiences with Red Sonja are from Savage Sword of Conan, which (to the best of my knowledge) Thorne rarely worked on directly* My first real comic book experience with the character was through the mini-series She-Devil with a Sword: Red Sonja, which led to the regular comic book.
From a logical level, the new Red Sonja attire is certainly more adventure-worthy than the chain mail bikini. Also Sonja is more athletic looking than in Thorne's work. From a feminist perspective, Sonja is less of a sex-pot, but if I remember correctly, they play with a potential lesbian bent to her nature — this is not really a problem for me, save that Sonja accepts no man who cannot best her, not because she is not interested.
One of the best parts about the 1980s Sonja is having Christy Marx writing. Ms. Marx wrote for numerous cartoons and comics (including Sisterhood of Steel, Conan the Barbarian, and Elfquest). I first came accross Marx's work in the PC DOS game Conquest of Camelot, which had a lot of mythological depth and a good story. Marx was very talented and was key to reviving the character for me.
All that being said, I am going to jump off the fence. I like the 1980s Sonja. She is different than the 1970s version, and has complexities of her own. I remember there being some really awesome covers, one of my favorites was:
* The Wizard and Red Sonja Show was, I believe, originally published by Eros Comics, and reprinted in SSoC.