As safe (or unsafe) as any other pedal. The X series is being phased out, so go for Light Action or Zeroes.
Advantages are double sided entry, low stack height, 15 degrees of float (or adjustable down to no float with Zeroes), spare parts, availability of long spindles, light weight, durable cleats, and serviceable bodies. Disadvantages are heavy, expensive cleats that need to be cleaned and lubricated periodically, and limited longitudinal adjustment for the cleats unless you buy the $30 extender kit.
I like my Zeroes, but I would not encourage switching over to a new pedal unless whatever you're already using is broken or seriously deficient. If everything is working for you, change your handlebar wrap and save money.