Hey Shane,
I have both the Shimano Beastmaster but 4000 version & Diawa Megatwin.
The Beastmaster only holds approx. 410 meters x 80lb braid, single speed with good retrieval speed about 160 meters / minute.
The Megatwin holds 1000 meters x 80lbs, 2 speed with auto kick down to low speed with high prolonged loads & also good retrieval speed about 180 meters / minute.
Both work great, pulled in 2.5meter sharks, 20 plus kg AJ's, had a marlin on etc and haven't missed a beat.
Another mate has the Miya Epoch, more commercial, 1000 meters x 80lb but slower retrieval speed about 120 meters / minute.
My opinion (that suit my type of fishing), the Shimano / Diawa are great for depths up to 300 meters.
The Miya Epoch for 300 meters plus.
All are good reels and only you can make that choice buddy