Yes, just do the research quietly, then buy the thing. If he opens a discussion you'll be able to say 'I'd prefer this one because...'
The argument against research is when it becomes disproportionate to the value and importance of the product, saps your time, your ability to be spontaneous and, potentially, becomes a crutch you rely upon to avoid anxiety and maintain tight control on every aspect of your life - which would suggests you had deeper problems.
I think the time issue is very real. Do you never have something better to do with your time than spending a morning or evening researching a product and doing this regularly? If you didn't need to make so much space for this sort of activity in your life, might you have learnt another language / read a lot of books / become very fit / played more with your children or planned more wonderful activities for them, by now?
I suppose I think the question is, if there was something else really important and pressing to do, perhaps chronically, how would you cope with decision-making? Would you be able to use short-cuts like brand, price, reputation and shop-assistant advice? Could you shorten your research process to look straight at the best buys? If you can do that when needed and live with the result, then perhaps you could save a lot of time whenever you choose to.
I suspect there's an 80/20 sort of pattern - the first 20% of research time reveals 80% of useful information, gaining a further 20% of info, mostly detail not critical to the decision in the end, takes 80% of the time.
Just try, as an exercse, going for 'gut feeling' in the face of many options, a few times. Then compare that result to your thoroughly researched one. I bet you've trained yourself well enough already that your 'gut' response is actually a very good one.