A few years back I nearly bought the Hw100 but I bought a new r-10 instead - BIG mistake. It had several problems, mainly the reg. Eventually repaired under warranty on their 3rd attempt, and then was promptly traded in.
Finally bought the 100 almost a year ago and its been flawless.
If you do choose the r-10, don't buy a new one coz BSA regs have a poor reputation and it would be a big gamble. Go for a Used one thats been fettled.
Or, you could just buy the Hw100