Originally Posted by
M60_to_LGA
The Metro is an adequate commuter system to bring people to their jobs and home again. And, yes, compared to other US cities it's a beacon - but the US is a third-world country

and the OP, who's from Europe, should know it has huge limitations. Furthermore, speaking as a former DC and Silver Spring resident who didn't own a car and relied on Metro as my primary mode of transportation, I can say with some authority that outside of business hours - and particularly on weekends - it's ...
Agreed. When the OP has dates booked he should then check the WMATA website for the planned track work and avoid the impacted lines if possible. It would be a pretty miserable trip if, e.g. he was staying up in Rockville and Red Line trains were only running every 25 minutes all weekend due to single tracking (there is also some weeknight track work).
The few times I have taken Metrorail have made me thankful I don't have to depend on it all the time.