HT or FS?

Hard-tail (HT) or full-suspension (FS)? That's my mountain-bike question of the day. My bike mechanic told me that the current bicycle I use “is shot” and I need something new. Problem is, I'm not getting any younger and my needs come with multifaceted requirements.

I'd like to keep riding till I'm in my early 70s, plus I don't want to spend a fortune on a new bike and yet, I'd love to get a lightweight little machine instead of the slug I push up the hills these days.

I know that older folks like me appreciate the comfort of full-suspension, but could my kind of trails, that are gentler and smoother, absolve any portion of that requirement and let me ride a HT?

Tough to decide, and the more I wait, the older I get and if I don't make a decision, I might miss on this fall's attractive mountain-bike sales...