Welcome!
I've done a 14-day cruise in an inside room and survived quite nicely. It's definitely a help on the budget. I wouldn't have been heartbroken to get an upgrade to a porthole room - a little daylight goes a long way (and you tend to sleep in less). Verandahs in my book are very nice luxuries.
Ultimately, if the budget said, "7 nights with a verandah vs. 14 night inside..." I'd go with the 14 nights.
When cost is less of an object... I'll compromise with an outside porthole. Cost is no object? Why stop at a verandah, when you can get a suite?