I don’t think he has the flair of Mahrez. I don’t fancy Ale taking on players from a standing start or doing sole rolls and twisting and turning. He needs to work on a trick or a method for beating full-backs one-on-one. His most efficient tool right now is getting in behind with a one-two.I don't think he's very similar at all. Ronaldo was much faster, especially over distance. I think for Garnacho to reach the next level, he needs to find a similar training program that Ronaldo used to improve his speed and strength. Too often Garnacho is able to get past his defender, but he struggles to keep ahead of them over distance, so I think the comparisons to Ronaldo and especially a young Giggs are not quite there. He's more Mahrez like in his approach - likes to dribble, great in tight spaces and a low centre of gravity. He's not the player to pick up the ball on the half-way line and run through the opposing team though.
On the brightside, he has shown that he has a fierce shot and a decent cross. These attributes can turn him into a world-class player until he abandons us for Real Madrid. He has a good base to be a top, top player but he just needs to add more attributes to his game so that he can be a threat every time he gets the ball.