Hunter DPS Help: Stats or Computer Issue?

Hey all, hoping to get some advice, thanks in advance.

I've recently stopped playing my pc desktop because of crazy loadtimes, and lag- despite it being an i7 w 4gigs of ram. So I've been playing on my macbook pro laptop. I'm definitely not as on top of movement and rotation when playing on trackpad, but playing on my desktop is awful with the 10 minute loading screens into dungeons and nigh unplayable lag in any place that is populated.

I'm reaching out because at il894 on my MM hunter I pulled ~450k dps throughout Heroic Nighthold, and I feel like I should be doing more. Profile here https://worldofwarcraft.com/en-us/character/stormrage/gaelanis . I know I should be stacking Mastery > Crit after haste is to like 11/12% but I'd be sacrificing so much in terms of ilevel. Is a 15point ilevel gap an upgrade if it's got lesser prioritized stats? Any help on the stats or computer issue is appreciated.