I love Pickering - very compact tree yet good vigor, great production, good looking tree with dense dark green foliage and short internodes, AWESOME tasting fruit with great texture, richness, no fiber, etc.
Had my first Mallika this morn allowed to ripen fully on the tree (hardly any green). Meh..... For a dwarf it's leggy, not well branched, fruit is a bit pasty with some edible fiber (that's not that objectionable). I severely topped it down to 8" when first planted and having harvested all fruit topped it back 1/3 yesterday past any of the long internodes.
Disclaimer - am a new mango grower, long time gardener, trees are young, greenhouse grown, greenhouse temps 99+ every day.
I've heard that NDM can get pretty large reason why I opted out for the other too.
Mark