You also have to look at lobe separation which for both is 110°...
Since both cams are ground on the same lobe centers, with the same intake center line, then with the larger advertised duration of the Howards will have more overlap and be a little choppier...
The Lunati has a faster ramp from .000 - .050 because it has lower advertised duration than the Howards... So it is covering the same lift in less duration - 268°/276° Lunati vs 273°/277° Howards...
Howards has a faster ramp from .050" to max lift because it has more lift than the Lunati at pretty much the same duration from .050"...
Keep in mind that the faster you close the valve, the higher the force on the valve and seat... So a faster ramp on the .000 - .050" will close faster with more force and wear on the seats - translation it will beat up the seats more with a faster ramp...
So with Howards having the slower ramp for opening and closing will be more friendly on your valves and seats for more durability.... The Howards will have a little more overlap and be a little rougher idle than the Lunati...
You will also have to run the proper valve springs and have your head guy make sure there is enough travel in the valve so you don't spring bind or bottom out the valve and break a valve... Any lift over .500 will need this checked and also check piston to valve clearance when you install it so a valve doesn't hit a piston which can put a hole in the block....