Just for the note: Doing dead stop training has improved my form a lot just in 2 weeks.
I don't know how you Deadlift, but like guys above said: just focusing on the form is more important than the volume when trying to get better with technique. Film your lifts, or if you have (reliable) lifting buddy, ask him/her to comment your form. Normally form is easier to handle with smaller weights. Smaller weights can be used also with greater volume.
As for the topic of the thread: Both are important. You should maybe read some articles about training volume, intensity and periodisation, if you haven't done that yet. General rule for many lifters is working in different phases from high volume and lower weight towards higher intensity, but lower volume.
Then there is some crazy shit like smolov, where everything is high (volume, intensity, frequency).