The basic profile of Rutherford is going to sound a lot like my preview of Mickey Moniak (6'2", 190 lb Center Fielder from California, with a commitment to UCLA, good speed and an average arm), but the actual profile is not quite a perfect match. Moniak was notable for his pure contact skills and well rounded overall game. Blake Rutherford is noted for his potential to eventually be a a bigger power hitter with somewhat better speed than Moniak.
Let's start the same way we did with Moniak and look at Rutherford's Defense and the elements that make it up: Speed, arm and routes. For speed, I've seen reports listing Rutherford as Above-Average and Plus as a runner. I've seen more reports Above-Average so I'll play it safe and take that lower range (though I'll add the note that the go to resource for draft scouting, Baseball America list it as Plus, with Plus-Plus potential. Above-Average to Plus-Plus seems like a really broad range for the one definitive, measurable tool a position prospect has). It's enough speed to cover Centerfield, regardless of where it falls on the scale. Rutherford, however is a player projected to fill out more than Moniak, so he's likely to slow some as he bulks up. For that reason many reports project him to a Corner spot. So, that brings us to his arm. It gets better reviews than Moniak's, but in the same way the Camry gets better reviews than the Accord. They're both perfectly fine and will get you from point A to point B, but you aren't really going to show them off. Rutherford's arm is playable in Right, but a better armed, similarly talented prospect could displace him to Left Field.
When it comes to routes and Defense, Rutherford is a few steps below Moniak (most everyone is). It's not really a knock against Rutherford, he's a fine player and can likely be Above Average in Center or Right Field. As a thrower, if he moves to Right, a team will likely work on his mechanics to use his momentum and lower half more as his current throws are almost all arm. Even all arm, he still can one-hop throws to Third base with good accuracy. Blake is intent on staying in Center Field and even as he adds bulk he may maintain enough speed to do that. Like his arm in Right though, a faster, better Defender could displace him to a Corner. His bat should play anywhere.
Which brings us to his bat. The first time I heard about Rutherford I went and looked up some clips. There's a good selection as he's been playing national showcases since he was a Sophomore in High School. My dumb luck led me to one of those older clips when Rutherford's swing was a bit more of a Rube Goldberg device with a few moving parts and timing mechanisms. The good news is that is long since cleaned up. There are some things in his swing now that I prefer over Moniak's. For one, Rutherford spends a lot of time in the zone with a flat, line drive swing. He combines that with quick wrists and good bat control, allowing him to adjust. He doesn't make the consistent contact that Moniak does, but he makes his contact hard. It's pretty tough to find any clip of him where he hits a weak dribbler. Even his ground balls are rockets. The video below is over 4 minutes of batting practice and game swings. I haven't seen it mentioned in any scouting reports, but it's noticeable here that when he chases it seems to be high pitches. Video from the Prospect Pipeline.
You may also notice in videos two different approaches, which is pretty advanced for a High School hitter. When Rutherford is swinging for power he uses a toe tap with a longer stride to close his stance and tends to pull the ball. You can then see him switch to a slide step without toe tap which shortens his swing a little and he tends to work a bit more opposite field. He can do this based on Defense or count. There's not a lot to nit pick about his swing. He rolls his front foot a little, the aforementioned potential for chasing (which I don't see in the video below from Fangraphs' Jesse Burkhart). It's a touch slower bat speed than Moniak to my eye, but a swing more geared to power than Moniak's.
In short, I'd be thrilled if I were a team that came out of this year's draft with Blake Rutherford. A potential 5 tool star with a great baseball name. I'm not totally sure I'd be thrilled if he was taken #1 overall though. He has very good tools, but no one "Wow!" tool. Prospects are often discussed in terms of carrying tools, the one tool good enough, by itself to get the kid to the Majors. For Moniak it could be either his Defense or his contact ability as a hitter. For Kyle Lewis, it's his Power. For Corey Ray, it's his Defense. For Rutherford, it could be his power, but that needs to develop. It could be his speed, but as we've seen with Billy Hamilton that speed is kind of useless if you can't get on base (the old adage "You can't steal First."). Rutherford's a bit of a gamble. The payoff is pretty big (maybe Jacoby Ellsbury with more consistent power and the one really weird outlier season).