Not sure what to do

I've finally done all the research I can on what Glock to buy ( G45 ). But I'm undecided if wither or not if I should buy and ordinary one ( non m.o.s. ) or cough up the extra cash and get the m.o.s. version. I'd personally would like to put a micro red dot on it ( finally got around to use one on a pistol ) and I'm sold on the micro red dots. I'm just not sure what would be the more secure way of attaching the optic. I've heard mixed reviews on the mos ( alot say it's amazing and alot say it's awful ) , but I've also heard that direct milling on the slide takes any where from 2 - 6+ weeks and I'd rather not be twiddling my thumbs when I could be out practicing and getting efficient with it. Thanks again for reading and giving me your input I've learned alot from this sub.