300 SD or SDL - Which is Better, and Why?

[Phalcon51]

This is a great community of enthusiasts! I've already gained much knowledge over just the last few days. Thanks to all who have helped so far.

I'm currently looking for my first Mercedes and just found out that the 3.0 L diesel engine comes in both 5 and 6-cylinder flavors! I was originally looking for an early to mid-eighties 300 SD, but now I'm wondering if I shouldn't move up the evolutionary ladder a rung or two.

I understand that the 6-cyl. is stronger, but can anyone quantify that for me in terms of power rating, acceleration times or just seat of the pants feel?

How would you describe the difference in power - torquier, more top-end power, better mid-range...?

Could I get your opinion as to which is better, and why?

Were there any major design changes, or did they just reduce the size of the pistons, add a cylinder and change the crank?

How do they both compare in terms of longevity/reliability?

What are the strong and weak points of each powerplant.

I've heard that the 3.5L 6-cyl. engine is one to definitely stay
away from. Does the 3.0L version share any of the same problems?

I prefer to do most of my own basic (and sometimes not so basic) maintenance. Are both engines equally easy to work on? Any caveats?

Thanks again for your help

Gary