The scales are easier, yeah. Once you've learned a scale starting on one position from one particular string, then you can just work your way up the fret board and that position never changes. Kind of hard to describe, more of a doing thing. But the tricky thing about guitar that I think makes it a hell of a lot harder (and/or more fun): there are a ton of ways to phrase every scale. For instance, with major diatonic, you can play three of the notes on the first string, three in the same position on the second, three on the third, three in that position on the fourth, three on the fifth, three on that position on the sixth. You could just as easily play two on the first, three in a different position on the second, three in different on third... so on and so forth. Bottom line: every scale can be phrased umpteen ways, whereas, say, on the piano, C major can only be played one way ever, so you don't end up being paralyzed by choice.

Eventually, this is a huge strength- as you play, you can choose whichever scale shape fits the phrasing of the song and where your fingers lie. But starting out... ugh. My best friend/best guitarist I know says that the best rule of thumb to go by is: pick the shape that requires the least amount of hand movement in terms of going up and down the fret board. This'll help insure that transitions from note to note and string to string are fluid.

My favorite exercise was always: (starting on the root) 1-3-2-4-3-5-4-6-5-7-6-1-7-2-1 and then back down. Once you nip that in the bud, it's fun to start mid-scale instead of the root.