Replacement for my 40 year old lyman furnace - RCBS Pro-Melt Furnace 120 V-ac - 81100

I am a very active bullet caster and have made a huge number of pistol bullets with my ancient Lyman 10 lb pot which still works just fine. With 6 cavity molds, the old pot struggles to keep up, hence my interest in this model. The Lyman furnace (Mag 25) had poor reviews, so I decided to go with this unit. So far it has worked well. The only problem noted is that after perhaps 45 minutes of operation, it tripped the GFCI breaker it was plugged into. I had to move to a non-GFCI circuit. I have not diagnosed this problem yet, but it is concerning. It is a lot lighter than the old cast iron pot but seems to be well made. Assembly instructions are a bit ambiguous, but after a false start, it went together OK. I would like to see an electronic/digital controller but the mechanical thermostat is OK. The unit got lost in shipping for over a week and Optics Planet was very slow to help find it taking over three days to simply return my call. The agent was polite but anxious to dismiss the call once I said the unit had arrived. I called FedEx and put a trace on it and it showed up 2 days later, although the package was pretty soaked. The furnace was fine however. So bottom line is furnace is good, Optics Planet is OK, but could use better customer support and maybe a better shipping company e.g. UPS.