Not familiar with that particular version, no telling the way Gaggia has changed things a bit over the yrs... BUT temp surfing is the same process with any machine, just a matter of finding a good/consistent range for what you're shooting for and repeat. Before I added a PID to the V1 Silvia I used quite awhile I'd run a few oz of water through the group, would start heating, then after it clicked off I'd time it around 40 seconds if I recall and then extract. That gave me a group water temp around 200 degrees F, exactly what I was aiming for. If I wanted a bit hotter I'd wait less time, a bit cooler more wait time. Once you get any machine dialed in it's quite consistent.
Is it as good as PID? Yes, just more involved/time consuming is the main difference. A PID likely saves a bit of electricity long term as instead of highs/lows with a traditional thermostat, a PID pulses tiny bits of electricity to the element to maintain water temp within a degree or two. Keep in mind that with a PID you still have to let it recover after each extraction due to cooler water being drawn into the boiler, just not hands-on as traditional methods.
