I am more concern with comfort, however, if it is ill fitting it probably won't work. I am a 46R - 17.5/35.
What say you?
Forgive me if this seems rude - but are you quite serious?
To ask whether one should try a different shirt fit without specifying common-sense details such as one's body type - especially since you mentioned that - or model/maker, or, for that matter, any context, is vague in the extreme. Collar and sleeve measurements and usual jacket size do very little to show whether one is overweight or skinny.
In addition, "slim fit" varies considerably between makers, with some taking the word for its true meaning and other simply using that label for shirts that are for normal people. This is a question that you cannot expect an answer from here - make the effort to try them on yourself.
Slim fit shirts can be very tight around the armhole. If you go made to measure, a standard fitting with darts on the back would be more comfortable. You provide the measures of chest and waist, but the armhole is wider. Of course it depends on the shirtmaker..
I agree with most everything above. I'm not slim at 5'10" and 215 pounds but can easily wear off the rack "fitted" dress shirts. I tend to like the Roundtree and Yorke brand available at Dillards and even with my extra weight their fitted shirts are a bit loose. I'm sure this varies by brand and shirts from European manufacturers may have a slimmer cut. If you are ordering online make sure they have a good return policy but if you are shopping brick and mortar, just try them on. Of course your best option is a bespoke shirt. Bespoke shirts I've had fit far better than anything I've bought at a store.