I had a VERY long relationship with a plain edged Co Pilot in Stainless Steel. As it is Stainless, it has a little heft. I took the clip off and used a stone to soften the minor sharp edges such as on the back of the blade.
Now that Co Pilots are discontinued, they don't sell for very much. But, they are mighty fine knives. A similar knife the is the "Navigator" with a "Truffram" coated handle. It is similarly sized.
These knives with the short but wide blades seem to be so much more capable than a common "penknife". With the handle to blade length relationship you feel like you have more knife than the abbrieviated bladelength would indicate.