Also, the first snap were 10 minutes, this second one is 4 minutes!

However if you look the log file sync waits

Code:
First SNAP without CTAS:
log file sync                                      56,757      225,427   63.60 

Second SNAP with CTAS:
log file sync                                       7,697      686,518   93.81
The wait time of second SNAP with only around 13% of first SNAP waits is MUCH MUCH longer than the first SNAP, clearly shows you have serious I/O problems with your redo log I/O subsystem

Code:
SECOND SNAP 

Event                               Waits   Timeouts  Time (cs)    (ms)   /txn
---------------------------- ------------ ---------- ----------- ------ ------
log file sync                       7,697      3,637     686,518    892    1.9
db file sequential read            87,472          0      28,547      3   21.4
log file parallel write               349          0       9,263    265    0.1
db file parallel write                256          0       2,547     99    0.1
log file switch completion             26          3       1,179    453    0.0
log buffer space                      108          0       1,043     97    0.0
buffer busy waits                     264          2         898     34    0.1
control file parallel write            82          0         677     83    0.0
direct path write                     161          0         372     23    0.0


FIRST SNAP

Event                               Waits   Timeouts  Time (cs)    (ms)   /txn
---------------------------- ------------ ---------- ----------- ------ ------
log file sync                      56,757          0     225,427     40    1.0
db file sequential read         1,729,916          0      93,853      1   30.6
log file parallel write            39,154          0      29,790      8    0.7
db file parallel write                576          0       2,203     38    0.0
SQL*Net more data to client       540,735          0       2,161      0    9.6
control file parallel write           206          0         508     25    0.0
log file sequential read            4,194          0         163      0    0.1
log file switch completion              5          0          75    150    0.0