Mechanically they are all about the same. We suggest look for reasonable prices, parts support with quick shipping, (you will need it

)
Shipping cost is another thing. You don't want to order a $3.00 or $8.00 part and pay $8.95 to have it mailed in a padded envelope.
Also check the parts prices before you buy. Some sell the helicopter cheap and then "put you to sleep" with the cost of parts.
If your local hobby shop is strong into helicopters and has good parts inventory, then shop there first by all means.
Just my 2 cents worth.