I have both Siig Minitouch 1903 and 1948, NIB. The switches are not real Alps. Alps were made in Japan, the XM were produced in Taiwan, then moved to China.
The Focus 2001 has real white Alps, and they are much lighter than the white XM on Siig. I also have a Monterey International with Monterey switches, and they are identical to the Monterey switches on the Siig 1948.
From the Alps family, I like the green Alps on Ortek MCK-101FTN, and grey Alps on Wang 724, or COSKEYBOARD.
The white Alps on SGI, AEKII and DELL, are stiffer than the white Alps on Focus 2001. It's probably the age of the board, which makes them lighter.
Somebody on the wiki said that Alps are very inconsistent, and it's true for me. Siig Minitouch with Monterey is a value, but the 1903 with white XM is not.
The construction of these boards is not strong, in the detriment of the switches.
Also, the layout of Siig is not the most enjoyable.