Although rear drags are easier to reach, front drags are consistently smoother. I've had the Shimano Spirex 2000 in both front and rear drags, and there's definitely a difference; the front drag reel is much smoother.

I also prefer the 2000 to the 4000 size, but I run thin diameter 8 and 10 lb line on the smaller reel (12 lb is not recommended). It holds between 100-110 yards; plenty enough for fishing, but if you break a significant chunk, you definitely don't want to hook a runner. The 4000 holds way more line than is necessary and is a lot heavier than most steelhead spinning and casting reels. Shimano could use a '3000' series, but until one comes along, I'm satisfied with the 2000.

You may also want to include the Spirex in your choices. I like the paddle reel handle for easy reeling, especially after first setting the hook when I'm groping for the handle. The Spirex also has a roller bearing in the line guide, making the drag even smoother. The Symetre has a bushing thats not nearly as smooth (I'm not familiar with the Sahara). Good Luck