Seattle Mariners organization discussion

I am now working on the Milwaukee Brewers Top 20 Prospects list for 2015. The next team in line is the Seattle Mariners, to be followed by the Washington Nationals, Detroit Tigers, San Diego Padres, Boston Red Sox, Pittsburgh Pirates, and the Houston Astros.

Use this thread to discuss the Seattle Mariners organization. Possible threads/question to discuss include, but are certainly not limited to,

****James Paxton, Taijuan Walker, Roenis Elias. . .what is your projection for each pitcher in 2015? Paxton and Walker were premium prospects of course, but Elias was a nice surprise. Can he sustain that?

****Are there any more Elias-like sleepers in the farm system who could help in the near future?

****How soon until Ketel Marte puts real pressure on Brad Miller and Chris Taylor up the middle?

****Is Gabby Guerrero a legitimate top prospect, or is he just a creation of a friendly park/league environment?

****As always, feel free to discuss sleeper prospects, over-looked players, or those you feel are over-rated.