Both can maintain hair and regrow hair in the crown area. However you are more likely to retain and thicken your existing hair longer term with Finasteride.
My point is that short term you could get good results from minoxidil but those results and retaining that improvement in the longer term is less likely in comparison to Finasteride.
The people that have documented online their minoxidil results and had good long term results appeared to have a slow progressive form of male pattern baldness.
If you are concerned regarding sides then it may be worth researching topical Finasteride and decide whether it is for you.
(These are my opinions only and other opinions may differ)