Having done this building thing for so long I find it interesting how the "standard" references have shifted. Back in the day you had (or all you could get from Proteus were) drop outs and track ends. Both were slotted for axle positioning (although only the track drops were actually horizontal). Now, it seems, just saying drop outs means verticals and horizontals refers to what I think of track drops. And if you say "drop outs" that means a cast design with a socket (or plug) to house the stay. I have seen this lack of detail to what a poster is really asking about. Not that this is all that big a deal. Just an observation. With the written word it is so easy to assume one thing when the poster is really asking about another style.

There are reasons that pros and manufactures use cast lugs and socketed/plugged drops. Making the frame easier to build is not why, as much as making it faster to finish and have it stand out in the market place (just look at Richard Sach's stuff as example). Newbies will find it easier to use fittings (and tubes) that have more range of options and aligning range. Andy.