Why I Chose Super Simplex?

My list of specific requirements for a first time build is lengthy and the Super Simplex meets most of them, so, in no particular order, here is the list!
1. Build Articles - Especially important for a first time builder like me. I know nothing about miniature locomotives. Even so, the Simplex build articles are far from complete, but, they are a good point of departure even if you know nothing.
2. Castings Available - Castings can be a real stumbling block. First there is pattern making, and then finding a foundry that will work with you. You can also make some things from solid instead of castings, but, you cannot beat the appearance of a real cast iron wheel. Castings also help speed up the machine process of making parts.
3. Tank Engine - By choosing a tank engine, you will not spend time fabricating a tender, or leading or trailing wheels and trucks on the locomotive. The choice is usually 0-4-0 or 0-6-0, I went with 0-6-0, as there are more wheels in contact with the track.
4. Imperial Measurements - Or, drawings that use inches for dimensions. I can work with metric, this is not really a problem, but, my shop and tooling is optimized for working in inches. Working in inches, just is simpler in my machine world.
5. Must be able to re-gauge to 4-3/4". There is no doubt about it, the catalogs from England have the best selection of 1" scale locomotives anywhere int he world. One little problem is, 1" scale locomotives in England are built to operate on 5" gauge track. In the U.S., 1" scale locomotives run on 4-3/4" gauge track. So, the chosen design must allow for re-gauging to 4-3/4". Locomotives with inside cylinders or have things crowded between the frame will usually not allow for squeezing the frames together  to accommodate 4-3/4" track.
6. Laser cut parts. The availability of laser cut parts will greatly speed up construction. Especially when it comes to connecting rods and valve motion parts. These laser cut parts will still need to be machined on all surfaces, but, are very close to the finished size.
7. Copper boiler build-able with the use of propane only. The boiler on the Super Simplex is small enough to be built by a single person using a large propane torch. A proper hearth must be made, but, it can be all silver soldered with propane and no other equipment.
8. Locomotive fire tube style boiler. There are other types of boilers used on first time build type locomotives, but, I wanted a boiler that is consistent with traditional locomotive type boilers. This allows for a normal firebox, flues, super heater, ash pan and other features found on most locomotive type boilers. Other types might be fabricated in a shorter time, but, are not true, traditional locomotive type boilers.
8a. Boiler should have a straight barrel, versus tapered. It can then be fabricated from a straight section of tube. The fire box should have a round top simplifying construction and staying. Also with a round top boiler, the outer wrapper of the fire box can be integral with the boiler wrapper.
9. Outside cylinders, valves and valve gear. I want to be able to enjoy and see all of the working parts that go into the construction of the valve gear. Also, outside valves are easier to adjust and set than inside type. 
10. Does not need to be a "Scale Model". I am interested in operating a miniature steam locomotive more than duplicating a prototype in miniature. Either way, the experience will be the same. Also, as a freelance design, it can be built exactly as desired. Detail can be as much , or, as little as desired.
11. Drawings available. Full size drawings are still available for the Super Simplex from several sources. They are a must.
12 .Proven Design. This requirement is so you don't have to "invent" anything. It is already done for you. If you want to make a miniature of your favorite prototype, this will really slow you down. Designing you own locomotive would be better for a second time build.
13. Coal burner. Burning fuel makes for a much simpler design. Burning propane or fuel oil will require more time to design and fabricate a system for these fuels. 
14. Plate frames. Plate frame are pretty typical for English type locomotives and are much easier to construct than the bar type found on most U.S. designs.
15. Reversing gear. Some 1st time designs use slip eccentrics for reversing the locomotive. I did not want to have to push my locomotive backwards or forwards to set the valve gear. I wanted reversing gear that operates exactly like the full size and also allows for "notching up" as does full size.
16. Slide valves. For a 1st time build, slide valves are certainly easier to fabricate and set than piston valves. While it is true that piston valves require less force to move from the valve gear, in a miniature, this is not really a problem.
17. Ability to haul several people. As witnessed on YouTube, the Super Simplex has plenty of power and can easily haul several people in addition to the engineer.