I have persevered with one of these for visual observing http://www.escience.ca/telescopes/RE...051/14593.html
with both a 102mm ED refractor (f/7) and also a 7" f/15 Mak. In practice, while the bearings are now reasonably smooth there are two issues:
a) using magnifications above 150X become difficult without slow motion controls;
b) locating objects - if you want some form of electronic assistance.
The Discmounts - while eminently solid and suitable for larger scopes - have no slow motion controls and pushing any decent scope around by the rear is simply inadequate to aim it.
That leaves the Half-Hitch Mk III as the best altaz mount around, apart from the one-arm fork SCT's from Meade.
There is no question the HH is ideal for your 102mm refractor - and fine for refractors up to 130mm.