Bound Bow + Fortify Archery + Sneak (+ Silent Casting*) is more rewarding and practical than any Destruction spells in my opinion. Even though the damage will not be as high as normal bow with Smithing + Enchantment but i found it already powerful. At level 45 on Adept, i kill many Dreuger Deathlords and Dragon Priests without major problem*. It is more practical than using Destruction magic.
Bound Bow damage can be upgraded with Archery perks, Conjuration perk, and Fortify Archery enchantment on gears, and Deathly Aim while Destruction magic not only weak, it is likely deal friendly fire on ally, no sneaking bonus and to beat an enemy feel like forever. Destruction Magic is just not practical for me.
The enchantment is also powerful, always active Soul Trap and Banish Daedra, i did banish some Daedras. With 100 Archery Paralyze perk, it is most useful, even though damage not as high as normal bow with Smithing + Enchanting, it doesnt really matter and it is better than any Destruction magic i say
* at the time i experiment with it i didn't focus on Illusion and have no perks at all, because my character is actually a non-magical archer thief, i cast Bound Bow before entering dungeons or far away from enemies, but i think with Silent Casting there will be no detection problem. Mercer say "you are too noisy for someone who claim to be a thief!" lol