The only major difference is that ETh as a solid team, a solid use case, a solid track record and if the price goes down now you know you have better chances of going back up if it ticks thoses boxes... Im not saying Sig doesnt have potencial but whatever goes up so quick must also come down the same way ( and you saw this happen with ETH and other major crypto ) its a gamble at the moment to mine Sig
You right. Don't mine signatum and don't buy. Wait for solid team, solid case and solid price. Absolutly without risk. Good strategy

I have been long enough on this game to have my own opinions... Not here to fud ( im actually mining SIG myself ) but thats not a reason for me to take my investments ( yes my rigs are my investment over some years, its my job ) without the proper reasoning behind it... Im mining it and can still admit that at this stage its a gamble because if price goes down quick all newb miners will start panic because they werent prepared for that scenario... Just my 2 cents