as far as ilevel goes, if you have the $$ to purchase legion BOE its the same for 101 and 109. i have yet to see a 101 who isnt fully, or on the way to filling every slot with at least the 840 BOEs.
the difference in ipvp between 101 and 109 is :more abilities from talents, access to all 3 artifact weapons, outside food-flasks work when you use them before entering bg and its easier/ faster to farm ap i think. follower missions with ap and rep rewards come in handy if you’re going to get fel focuser on a 109. and you can get the first level of resesrch at your class hall, which is the chance for epic upgrade on non repeatable loot. a smart guy, not me, would have levelled up to 109 THEN DO ALL THE QUESTS in hopes of scaled up purps for things like trinkets and relics. next time maybe.
your stats outside of a bg as a 109 aren’t stellar. you wont be soloing any legion dungeons.