If you want a simple low cost option, the Garmin FR15 has served me well. Cost me $85.
There's a cheaper FR10, but the battery life isn't as good supposedly. The FR15 will comfortably last a marathon and then some.
I'm not certain if it could upload to Strava, or if it does, might take a few clicks. It uploads identical data to Garmin Connect, you might be able to link it.
Takes 5 minutes - 30 seconds to locate GPS depending on if it's a new location or not. Shorthand summary is that it has two screens that show two items. You can do lap time, lap speed, lap distance, total distance, total time, total speed, pace(lap), pace(current), pace (overall) - can only pick 1 pace option in total though for both screens sadly (I do pace/ lap which defaults to a mile but can be changed, and total distance).
It's a lot more accurate than the GPS on my phone, that's for sure.