The X-Bow is a great choice to deal with a large number of small troops such as Skeletons and Goblins as it can hit every 0.3 sec.
Also, the attack range of the X-Bow is pretty awesome (13 tiles), it can be used offensively as it can attack the enemy Towers over the river in game.
Rocket, Fireball and Lightning are very useful at dealing with the X-Bow since you can use them to deal damage to anywhere on the battle ground.
It takes 5 seconds to deploy the X-Bow so you can prepare to deal with it during this time by using either building-targeting troops or a large group of troops.
If you use X-Bow in offense, make sure you have a meat shield for it once it gets locked on the enemy Tower.
Level
HP
Damage
DPS
1
1000
20
66
2
1100
22
73
3
1,210
24
80
4
1,330
26
86
5
1,460
29
96
6
1,360
32
106
7
1,496
35
116
8
1,640
38
126
Changelogs
On 2/2/16, decreased the X-Bow’s hitpoints by 15% and now only target ground (from air & ground).
On 9/2/16, increased its deployment time to 5 sec (from 3 sec).
On 23/3/16, decreased X-Bow’s attack range from 13 to 12.
On 21/6/2016: Deploy time decreased from 5s to 4s, HP increased by 18%