Charles,
On one hand you say...
It is such a simple requirement at it's most basic level (well suited to FOSS) - just a list to replace a box of dog-eared contact cards. However, all the current offerings have embraced complexity and have tried to offer 'all things to all men' becoming unfocussed and needlessly complex.
And on the other :
BASIC REQUIREMENTS:
Blah....
HIGHER LEVEL REQUIREMENT:
- Being able to synch 'Next Contacts' into a central calendar or To-Do list (Tasks list)
- 'One-click' telephoning of customer (needs headset) - Dolibarr has this
- Geo-locate - e.g. if I have a business meeting in Birmingham, who is nearby or on-route that I can have a quick meeting with / invite to a little seminar / have a beer with etc.
- Marketing - ability to do targeted mailshot with relevant info / offer - quite a few CRM's offer this
Some things often sound so simple (geo-locate etc), but take a much higher level of complexity to implement, and your requirements aren't necessarily that simple !
Your Higher Level requirements are completely at odds with your KISS thoughts.
I think you are either going to have to keep it simple and forego a lot on your wish list, or bite the bullet and go for something much more complex - not that it will make any great difference in use to your server if there is only the odd user on it.
vTiger is a good product - just a shame their attitude on 'Open Source' sucks ! YetiForce is a fork of vTiger 6.x with quite a few improvements, but despite promising a brave new world, they are as bad as vTiger IMHO.
Another thing you may consider looking at is another vTiger fork called CoreBos - this is primarily based on maintaining and improving the solid vTiger 5.4 - the boss of the company that run it is a very nice guy called Joe Bordes. He can help you with customisations etc.
So in short, it's make your mind up time. KISS or all in
B. Rgds
John