The links are from NFLdraftcountdown and are usually pretty good. So, I'll get some info from from NFL.com. The description for Williams is as follows:

Positives: Adequate upper and lower body build. Reliable hands, and can extend and snatch the ball outside his frame. Adjusts to low and high passes. Lines up outside, in the slot, on the line and as an H-back. Used on quick screens to get the ball in his hands. Always seems to find the hole in the zone to present a target. Sells the fake well, getting his head around quickly to find the ball. Lowers his pads to bowl over defensive backs and get extra yardage. Has some elusiveness and ability to break tackles in the open field. Fair release off the line, and uses his hands to free himself of jams. Good blocker downfield, getting his hands inside the jersey and sustaining with quick feet. Used on special teams coverage units and is able to wrap up or pound return men on the fly.

Negatives: Finding a position may be an issue. Below average height and strength to play tight end or H-back, but was not used as a lead blocker in Idaho's offense. Struggles to anchor or sustain blocks against defensive ends or bigger linebackers. Will cut block, albeit effectively, in pass protection instead of standing up to blitzers. Doesn't have the straight-line speed to threaten the seam or separate from NFL linebackers and safeties.

And for Mitchell:

Positives: Rare height and arm length for the position. Good straight-line speed to challenge deep. Can track the ball over either shoulder and shows good body control and field awareness to keep his feet in bounds. Soft hands to pluck the ball out of the air and can make the reception outside of his frame. Alert receiver who will work his way back when the quarterback is under pressure. Good leaping ability. Shows a bit of vision and elusiveness as a runner after the catch and has the long strides to pull away from smaller defenders. Uses his size and length to effectively run block against small corners.

Negatives: Much of his production is due to this offense. Good, not great, straight-line speed. Will be caught from behind by NFL corners. Long-strider who has to build up to it. Lacks the short burst quickness to consistently gain separation against elite cover corners. Sinewy frame that may not withstand NFL punishment. Ball security may be an issue considering his lack of upper body strength. Isn't the dominant red-zone target his size indicates, due to marginal toughness and physicality in going up for the ball in traffic. Allows too many passes to get into his pads, resulting in some drops.

Depending on where you look, Williams is listed as either a TE (as in college) or as a FB. This leads me to believe he will be a FB in Washington, in sort of a H Back type of role. At 6-1 and 240, he's got some size. He played all 4 years at Idaho, so he's got some experience. According to NFLdraftcountdown, he ran a 4.8. I can't find any time for him on NFL.com, but they do have him down for 23 reps. Spped and strength. Not bad for a ST player.

The thing that jumps out at me for Mitchell is his size at 6-4, 218. He's got 4.49 speed, which isn't bad, especially for a 6-4 guy. He's only got 9 reps (nine!) at the combine. For a frame of reference, Bey had 16 and Harvin had 19 (Crabtree and Maclin didn't do much). All his other times and reps are pretty good, but nothing jumps out either good or bad.

I'll try to put a full recap up later (if sugar or KevinE don't beat me to it) but the biggest thing that jumps out at me from this draft is no OL. I hope (fingers AND toes crossed) that they go after some UFAs, a la Heyer.

All in all, good draft, especially considering the lack of picks coming in. We'll see how the UFAs shake out in the next week or so... but not bad additions.

Images via media.scout.com and media.lvrj.com