The Machame route is also called the “Whiskey Route“, a reference to the “Coca Cola Route” Marangu (see above). Machame is “tougher” than that.
Machame is indeed a more difficult climb in some respects, but it does have much higher success rates than Marangu, especially if you choose the seven day version. (According to estimates about 60% of the climbers on Machame make it to the summit, and over three quarters reach the crater rim.)
The seven day version gives you a very short day before your summit attempt, which leaves plenty of time to recover, acclimatise and get ready. The six day version has the same problem as the Marangu route in that respect. See above.
The Machame route is not technically difficult. It is more strenuous. The trail is often steeper and it involves many ups and downs, crossing a succession of valleys and ridges. But that’s why it is also one day longer than Marangu.
Still, for people who have never done any longer hikes in their life and are not well prepared it can be demanding and tiring.
There is also the Barranco Wall to cross, a very steep, one and a half hour climb that will require you to occasionally use your hands for balance. (It sounds and looks a lot more difficult than it actually is!)
Well, and you have to camp all the way. If you go with a budget operator that alone can be demanding, especially if the weather turns bad.
As for scenery, the Machame route is absolutely spectacular: the Shira Plateau, the Lava Tower, the Barranco Wall… You start from the west, circle Kibo on the southern side, and then descend on the Mweka route in the south east. The variety is hard to beat. Machame is considered the most scenic Kilimanjaro climbing route.
For that reason the Machame route has become the most popular climb route on Kilimanjaro. The advantage of that is that prices have dropped and you can find many budget operators on it. The disadvantage is that the Machame route is very crowded.
If you are confident in you ability to hike in difficult terrain for days in a row, if you like camping and nature, but money is very tight, then Machame may be the Kilimanjaro climb route of choice for you. You will have to put up with the crowds
The route approaches Mount Kilimanjaro from the south, beginning with a short drive from Moshi to Machame Gate. The path leads hikers through the rain forest to Shira Plateau. Here, many of Kilimanjaro’s routes converge. Then the route turns east and traverses underneath Kilimanjaro’s Southern Ice Field on a path known as the Southern Circuit before summiting from Barafu. Descent is made via the Mweka route