In my expereince the HEI units available for the 2F are well designed and not just "slapped together". I ran one in my 2F for years and it was trouble free. If you buy one made specifically for a 2F like the unit sold by DUI, it is designed and built specifically for that engine. The feeling that some of the early HEI units were slapped together resulted from people taking distributors built for Chevy 6's and dropping them in. They would fit but the angle on the gear teeth was slightly off and would eventually grenade. The new ones do not have that problem.
The nice thing about the HEI units is they are simple to install (1 ignition switched 12V wire) and the cap and internal parts can be bought at any parts store in the US since they are GM components. They also give you a very hot spark which allows you to run a larger gap on your spark plugs. This will help in an older engine where compression might be down a little and will help minimize plug fouling. Due to the newer design they are less prone to shorting out if they get wet. I used to power wash my 2F directly and it would always start right up.
The down side is they are pricey. If you are trying to keep your rig authentic then stay with the proper OEM ignition setup. That system works fine when installed properly and the components are in good shape. If your distributor is worn out or you are going to have to spend a fair amount to find replacement parts, I would not hesitate to go with an HEI unit.
Randy Rosetta KDØKWX TLCA #19351 2015 Rubicon Hard Rock & (2) 1970 Boss 302 Mustang's