So what is so bad about a mountain bike for an all purpose bike? I never knew it to be bad until I got to this forum, than I quickly learned many reasons.
Pros of a real road bike: Lower weight, lighter skinnier tires with less resistance, and sitting parallel to the ground for wind resistance.
Pros of a MTB for a cylde: stronger rims for riding up a curb, through a cracked up street, hitting smaller potholes, with road tires available. Sitting upright for me is important, my doctor said to ride a bike upright due to my hiatal hernia. They have some fork shocks to take some of the load at the expense of weight.
If you have to sit upright, what would be the ideal bike? I would hat to invest 100 dollars on a comfortable seat, and 50 or more on a new tire set if the bike isn't right for what I need to do.
You might be asking why I don't ask this in the MTB forum? Because they think a MTB is for trails only, people get blasted when it comes to talking about slicks.