Champion 3500/4000 here, and I love it, although I don't use it camping (boondocking) any more. Main reason: It is HEAVY and BULKY. It is IDEAL for home backup.
I've owned my beloved Champ for 6-8 years now, and it continues to start on the first or second pull. I store it OUTSIDE all year, and start it and run it every few weeks. It sits out in the rain, it's had snow piled up on it, and it keeps starting on the first or second pull.
If I were the OP, I would analyze my power needs and look carefully at the plug and power config of the 7500. IIRC there are several models and I looked at buying one but found that they really seemed to offer twice the pluggage of my 3500, but no single plug that offered all 7500 watts.
So my recommendation is to buy two of the 3500/4000 units, for less money, same power and twice the reliability in a pinch.
I love my Champ!!