Personally, I prefer the L78 if one is going to retain the original speed control handle and/or on/off switch handle, and platter mat. Otherwise they are the same, except for the auto return feature, which I dispense with, anyway.
I am one of a growing few who have both a restored 301 and restored Lenco. I am with GD in favor of the Lenco for first-time or less than confident restorers since, as he says, it is cheaper and easier to "sort out". If you have confidence in your restoration abilities or are having someone experienced do the work, I might choose the 301, especially the early hammered finished ones. I really prefer the look of them, though you CAN paint the Lenco top plates almost any color (which we have done to great success). Performance-wise, I prefer my 301 by a shade, but it very well could be the combination of arm and cartridge that make the difference, which is slight. Objectively, there is probably not enough of a difference for most and in most systems. YMMV
In the case of either table, the effort required to restore the mechanicals and build a proper plinth which can, at the same time, look great within your decor (if this is important), is not as slam-bang as some might have one believe. Don't get me wrong, it is not rocket-science, either, and to get decent results one needn't be a mechanical expert or own a wood shop. Things can be disassembled, cleaned, lubed and re-assembled without a ton of experience and without special tools. Too, a decent plinth can be formed which will suit many. However, if one runs into mechanical difficulties or has speed, hum, or noise problems or if someone wants a furniture grade plinth, there is a lot more skill, time, and expense involved than one might assume going into a project.
I can say that the effort spent on both the 301 or the Lenco will yield great results, whether done by ones self or by someone else. I could go on, but why bore people? ;-)