I've been using a flat bottomed 58mm chunky alluminium tamper that I bought secondhand with my Silvia a few months back. I've been using a La Marzocco double filter basket for a while now and do still occaionally under-dose a fraction and the tamper hits the ridge. I'm wondering if a convex tamper would help alleviate this problem, thoughts anyone?
If a convex one would be good, what should I go for? A lot do seem to be over-priced fasion items for what is basically a wooden handle (in most cases) with a lump of alluminium or stainless steel on the end, or am I mis-judging them?