MLB seems to have a much better handle on Cuban ball players than I though. Here are all the Cuban ballplayers signed since 2010. Credit to Wikipedia for most of the information. There is not one major bust out of all of the big money ball players.
Admittedly, the jury is still out on Martin, Arruebarrena, Geurrero, Gonzales and Iglesias, but all of those guys are brand new except Martin. Leonys Martin has stuck at CF for the Rangers for two years now, and has a career .257/.311/377 triple slash line. Before you start calling that a bust, consider Dustin Ackley's career slash line of .246/.312/.356. And Ackley plays left. Having a serviceable center fielder who is not a black hole with the bat might be worth $15.5 million.
It is unclear whether MLB thinks Castillo is a big money ball player or not, but teams have not been getting embarrassed by their Cuban signings. Some of them have been wonderful. How about Roenis Elias?
Leslie Anderson
Outfielder
2010
1.725 mil
Roenis Elías
Pitcher
2010
350 k
Leonys Martín
Outfielder
2010
15.5 mil
Yoenis Céspedes
Outfielder
2011
36 mil
Gerardo Concepción
Pitcher
2011
6 mil
Adonis García
Outfielder
2011
400k
Roberto Carlos Ramírez
Shortstop
2011
?
Jorge Soler
Outfielder
2011
6 mil
Henry Urrutia
Outfielder
2011
778k
Dariel Álvarez
Outfielder
2012
800k
Aledmys Díaz
Shortstop
2012
2 mil
Yasiel Puig
Outfielder
2012
42 mil
Omar Luis Rodriguez
Pitcher
2012
4 mil
José Abreu
First baseman
2013
68 mil
Erisbel Arruebarrena
Shortstop
2013
25 mil
Yenier Bello
Catcher
2013
400k
Daniel Carbonell
Outfielder
2013
1 Mil
Rusney Castillo
Outfielder
2013
NYS
Odrisamer Despaigne
Pitcher
2013
1 mil
Miguel Alfredo González
Pitcher
2013
12 mil
Alexander Guerrero
Shortstop
2013
28 mil
Dalier Hinojosa
Pitcher
2013
4 mil
Raisel Iglesias
Pitcher
2013
27 mil
Orlando Pérez
Infielder
2013
NYS
Misael Siverio
Pitcher
2013
NYS
Yasmany Tomás
Outfielder
2014
NYS