I have both and honestly i am quite happy with them professions :3
Enchanting: 2x160 = 320 int on rings
Jewelcrafting 2x320 int in various sockets in place of 2x160 = 320 int
Leatherworking: 1x500 int on bracers in place of 1x170 = 330 int
Alchemy: Mixology grants a bonus to your intellect flask: 320 int
Blacksmithing: Two extra intellect gems: 2x160 = 320 int
Inscription: 1x520 int on shoulders in place of 1x200 = 320 int
Engineering: 1920 int for 10 sec on-use, one minute CD = 320 int time averaged
Tailoring: 2000 int for 15 sec proc, one minute ICD = 500 int time averaged, in place of 1x180 = 320 int time avreaged
all professions give the same bonus, 320 int, with the exception of LW which gives 330 - not worth to make a fuzz over imo.
The tailoring and engineering can become stronger if you think them into our play and stack them with other cooldowns.
Tailoring allows you to make a cheap version of the intellect leg enchant, for own use only, which makes it a good pick for a mage. Enchanting is overall nice and easy to level