i'm running 11spd Ultegra on my new bike and i cannot seem to quite get the gears aligned.
it always seems to feel quite sluggish and not sharp.
any ideas on how i can sort this out?
I had no problems after installing the Shimano 6800 11-speed groupset on a new frame. Your issues sound like cabling might be the cause. Check that the radius on bends is not too tight and that the cable outer enters the rear derailleur straight as explained in the Shimano Dealer Manual document DM-RD0003-02-ENG.pdf on the Shimano website.
I assume you are using the correct cables for this groupset.
Also make sure that you have followed the Shimano instructions (DM-FD0002-03-ENG.pdf) for cable routing for the front derailleur.