Which HAA company has the best bennies  

16+ years at a Rocky Mountain/Air Methods program, very happy there. Overall, good maintenance and little management second guessing, limited spares when base OOS for maintenance. My only issue was recurrent in Colorado- terrain and weather had nothing in common with my assigned base except days and nights were common to both.

The last few years were organized/union, which made an enormous difference. Some dissension amongst pilots in losing the capability to cultivate 'favorable' relationship with management, but it was always favorable before and after union- the union leveled the playing field for bidding open positions, workover, etc.

Every program base is a unique individual due to interaction of medical side, maintenance and the direct management style. 

"... used the bennies and if they covered as promised." 

Air Methods delivered bennies exactly as promised.

"Also who has the best retirement package?" 

My memory is that retirement was an individual account (401k?) with limited company match (1/2 your contribution up to 8% = 4%?). Self directed investments?