A sample level 50 RR (sample because shield parts make a big difference) is +24917. Base level 50 health is 36058.
That particular one is Hyperion/Maliwan/Maliwan which happens to be perfect (an inferior parted RR should be around 20K). This gives a roughly 70% boost, double that of the BL3 version. DR is essentially the same (20 vs 23%).
A level 72 shield has +366620 health. Level 72 base health is 530564. Hey look, +70%.
How big a deal is that? BL2’s best RR users were Krieg and Sal (so much so that I didn’t use anything else). I’m not experienced enough with BL3 to be able to rate the BL3 toons’ passive healing and shield-down skills, but the primary question really is : does it do the job?
So does it? Seems to for me. Would I like more health? Sure, but extra health is available on grenades, COMs and relics.
And the potential bonuses to melee, speed and/or reload certainly make up for it.
And, who cares if a level 1 shield does the same job as a max level? Saves a trip to The Bulwark