I prefer to attach my release directly to the string rather than using a loop. is there one type of release (style, type, brand...) that works better than others for this. thanks.

I am not sure if ones any better than the others or not. I use a Cobra release and have enjoyed great sucess with it. ( Off The String )

I use an Ultra Nock and a TRUEFIRE release .
If I were to shoot off the string , I think I would use the release called the Gator . It grips the string aboce and below the nock .

When I shot a wrist strap release the one I like most for hunting was the Fletcher Fletch-hunter. One thing I can assure you is that it was very easy on servings.

Personally I use a rope release. Cascade Model 8 to be precise.

I have been very fond of the Winn Free Flight releases. Have used them for years and haven't had any problems. Easy on the serving and very smooth releases.

I use a Scott sabertooth and it is very easy on the serving. A little pricey but well worth it.

I shoot off the string as well with a Cobra Black Mamba - I like the design, which was made for that purpose, and the trigger feel.

I used to shoot a Winn release, and it did great off the string, the only knock on it was that it is a "glove" style release and I couldn't get it out of the way when I needed to use my hand.

Either will work very well off the string.