Changing derailleurs
 

i currently have alivio front and deore rear deraileurs and deore shifter pods. will it make a diffrence if i upgrade both front/back with both LX or both XT or LX front and XT rear, without upgrading the shifter pods?

thanks in advance.

If it woks ok,why fiddle with it?

I'd say maybe if you jump to the xt you might notice a little, but only if your comparing a nicely tuned deore/alivio to an xt. I wouldn't bother just going to the lx. I have heard people say that sometimes the shifter pods actually make a bigger difference.
I just put an xt pod on my front deraileur, replacing the alivio. I cant tell the difference in actual shifting (though i must admit i didn't have time to truly dial it it) but to the finger it feels like a more solid product.
If your looking for good shifts, i would recomend just upgrading the rear derailer and pod. I personally dont use the front shifter much, probably 2-3 shifts in an 1 1/2 normal trail ride.