I'm still a green horn and still learning on my UDS so I can only speak from my experience over the last few weeks. I have tried mixing lump and Kingsford briquettes and I have used briquettes only.
The mix lights faster, seems to burn a little hotter but also had me tinkering with the ball valve more to handle temperature fluctuations. Take off the lid and she really gets going and is hard to get the temperature back down.
Plain charcoal on the other hand is a little tougher to light but burns longer and steadier, seems to hold the set temperature better for me. This is what I use for all my cooks now.
As far as taste, hell everything seems to be good off the UDS if cooked right.
I have also found that if I need to do much work under the lid, wrap in foil or turn meat, that if I take lift the grate out with the meat and put the lid back on to keep air from getting to my fire, do what I have to do, then put the meat back in, it keeps flare ups or heat spikes down to a minimum. In other words, keep the lid on as much as possible.
Just my 2¢ worth. Hope it helps.