SONM project is much better than Golem...
Dev team release every promise on time, with livenet it will be possible to run every application & rent every PC components... I sold all of my GNT for SONM!
SONM has 62 million USD total marketcap and GOLEM has 234 million USD total marketcap. Golem is nearly 4 times higher totalmarketcap than SONM at the moment.
Marketcap means nothing, look at EOS. Sonm is currently heavily undervalued because golem has first mover advantage. Then again, Sonm actually has a live mainnet, golem has not.
Can I mine cryptocurrencies with Golem? Or would it be far more efficient and cost effective to simply convert Golem (GNT) into the desired currency on an exchange.
You can with sonm, or to be more precise, it does that for you, whether you're in the business of mining or not. When you sell your computer power, sonm determines what's the most profitable option, either it mines cryptocurrency or it performs tasks. Right now the mainnet isn't operational for non crypto features, so the mining option will be the most profitable