I often play these builds by turns because both are great options imo!

Everfrost build feels less offensive, but a lot safer - smaller damage output gets negated when you can use the extra stun - literally a free Q hit, which is a lifesaver (especially against champions with high mobility like Yasuo, Le'Blanc etc).

I choose Luden's build, however, when I feel like playing more aggressive and one-shotting enemy champions at f.e. 50% hp even if they're tanks (f.e. Illaoi or Teemo feel like great champions to play with Luden's against due to their low mobility = free Q hits)
Playing with Luden's gives you less safety obviously (is more punishing), but the damage output can be really worth it :D

Sometimes it's just good to adjust the build to your enemies.

Hey whitekiba. Cho is a poking mage and yes, missing Q can often be a death sentence.
1) Use fog of war (behind the wall or bushes) to hit Q. The higher the elo the more often enemies will dodge your Q.
2) When trying to catch someone use Q slightly in front of the running enemy, so he's forced to move back to you a little to your / your allies range.
In laning phase you can spam using bushes. Study your enemy's movement when he's csing. Punish him for csing (if you have Dorans already). Maybe if you can one-shot enemy, stay in bush and let the enemy freely kill minions wave, so he feels safe thinking you're not there and when he goes in a straight line for the turret you get an easy Q hit ambush attack.