Better rTMS studies? Where are we headed??

Browsing Pub Med for TMS related subjects and came across an article whose authors include Dr. Pascual-Leone and Dr. Fregni, both from Harvard. They did a meta review of TMS (and incidentally a both prolific researchers looking at rTMS, tDCS etc..) and it's effects on depression from articles published in the last year and it seems that there is an improved effect of TMS on depression in these papers versus earlier studies.
Is this a result of improving science behind the use of TMS, more accurate TMS protocols, more studies????
Anyone have any thoughts on the subject????

Has repetitive transcranial magnetic stimulation (rTMS) treatment for depression improved? A systematic review and meta-analysis comparing the recent vs. the earlier rTMS studies.