switching from typical wkout to volume

[Steele]

I have been working out the traditional way: 3-4 excersizes per body part 3 sets with 80-85% max weight.
now, i am considering switching to volume training: 20 to 30 sets and use 65-75% max weight. and go for the pump

anyone make the switch? what kinda results should i expect?
by the way, i am a hardgainer, but juice

[yellows2k]

IMO, I think you would get weaker at first since you are using less weight so your muscles will think it doesn't need to be utilized to its full potential(80-85%). But on juice and constantly working from 65% you should get stronger and then when you make the switch back, your 80-85% will most likely be stronger. The pump doesn't mean anything