Make no mistake about it, 50' of 2" hose (flexible) will make a difference over 25' of 1.5".
By adding the 2" hose, you can make full use of the 2" barb on the tank (the mytee will come with 2" already, they use a reducer cuff on the "package" 1.5" hose), then run your 50' manly hose to your wand or rotary tool direct using a "vac attack" adapter, guys like Olson will have the flex hose and the vac attack in stock.
Another option will be a Cobra hose, it's 25' of hose that starts off as 2" and slowly tapers down to 1.5", very popular with mytee machines, can be added to a 50' section of 2" for that 75' reach in the master bedroom or used solo for just cleaning a couch off the front door.