I haven't tested the Patriot Supersonic Elite yet, but if you don't need the insane random read/write performance of the Corsair GTX, then the Patriot "should" be fine for simple file transfersMost reviews were ok for the Sandisk and it is better priced where I live ($58 vs $77). It seems the Corsair has a full SSD controller on it which helps with sequential operations, but I doubt I'll need to work directly off of it. For regular read/write operations they're fairly similar.
I'll see if I encounter performance degradation like you did over time. If I do then I'll just avoid it and buy something better. Thanks for the advice.
Patriot Supersonic Elite
128GB is $22.99 @ Newegg
256GB is $37.99 @ Newegg
Sandisk Extreme "Go" 128GB is $31.92 @ Newegg
Sandisk Extreme "Pro" 128GB is $44.85 @ Newegg
Corsair Voyager GTX 128GB is $50.99 @ Newegg