I am actually a huge hybrid fan. But hybrids aren't for everyone.
Pure int is fastest for grinding and lvling. Though hybrid is close because they can grind on higher lvl mobs. Pure int tries to 1 nuke or nuke+lion shout a mob. A heavy hybrid can't 1 nuke a mob so I try to fight a higher lvl mob, that would take nuke+knockdown, or 2nukes.
Hybrids tend to do worse at lower lvls like below 42. Not really sure why.
The more str you add the weaker your nukes become and the more you rely on your weapon skills.
There is no magic stat distribution when making a hybrid, which is why I like to go by magic balance. It isn't the most accurate (might be off by 1-5points) but I think it gives you the most freedom to experiment. For s/s I would recommend anything from pure int to 80% magic balance naked, if you still want to nuke. Though most people would say 85% would be the absolute lowest for s/s.
http://bobtheveg.dyndns.org/SRO/Char_Build_Applet/If you go here, click on the head icon, and raise the lvl, you can see how hp and balances are affected by where you put stat points. So lets say someone recommends a 1:7 build, here you can see what the balances of that build are. Just like most people don't relize that a 1:2 is almost the same as a 70:70 balance build.