A tapered leader will turn over and straighten out easier than just a solid length of mono. Large flies will often pull the leader straight anyway due to their mass and that's why some bass fishers don't mess with tapered leaders. But you'll get better turn over and a more delicate presentation with a taper leader. It doesn't really matter if you buy a tapered leader or tie your own, both styles work.

I agree with George's comment about the lb. breaking strength is more important that the "X" value.

there was some leader in there.

Well, so many variables. It didn't like something

I started out fishing tapered leaders I picked up from bass pro. Really and truly this is ideal for me. the presentation of the fly with a Tleader is unmatched in my opinion. Ill just pick up some heavier tippet and a few new leaders next trip, and know that if worst comes to worst. Mono works...I guess.

How are your fly casting skills?

Are you able to lay the fly line itself out straight and tight with just the leader being the problem?

My casting is So-So. I cannot however false cast. Mine are not effective or pretty to look at. more like dangerous haha
So I keep to the cast and settle and grow my cast from there.

today there was hardly any wind when I was out there. The casting was better, but still not as good as tippet/tapered leader.
I caught 3 little one pounders, no big fish.
it works, just not ideal I suppose.

6X...huh? Only on the San Juan River in NW New Mexico...bass just hit too hard. You might just try some 1 or 2x tippet only when targeting bass. You don't need a gentle float down to the water for bass. You have to withstand the initial strike, then the turn to run.

Like MickFly wrote, the guy at BP needs to be fired for recommending 6x for bass.

This could also be a function of the length of the mono. If the fly slaps the water, add a foot, if it doesn't make it to the end (Puddles), cut a foot off. The length won't be the same for every fly, unless it has the same weight and wind resistance, so you might have to adjust it for each new fly.
The good news is, Mono is cheap. The bad news is, it takes time to tie the knots. I always use a double surgeon's knot. It's fast, easy, and it holds well in mono, but is weak enough to break when you need it to. Please, be sure to put the cut-off bits in your pocket.

Kirk

Just my observations. I like what Robert Hunter suggested. I have watched him fish and the guy can catch them when others are wondering what the heck is he doing. Secondly, I've caught a few fish in my life time. In stained water I make my own leaders from standard 8 lb. fishing line. You should be able to play even some of the double digit fish I've landed with this strength. Way cheaper than fly store leaders and tippet. I've gone down to a size 18 fly with this line so it will go through the eye of the hook. In clearer creeks/ponds/rivers I use fluorocarbon. I have not tried the brand Robert suggested, but I will. I seldom use a leader over 7' in length. I can see strikes quicker with a shorter leader and see soft takes when the bite is light. When the leader gets too short, I cut it off and quickly tie on another one and back to fishing. A perfection loop enables connection to the fly line loop. Takes only seconds to tie it.