Yeah, my understanding is when new block hits you are better off starting to line an empty block than figure out what txns to include before you start searching. A short time after you can build non empty and try for fees.

So Monero fees are interesting, because since the blocks generally aren't completely full and there's no transaction backlog, you can pay virtually no fee and be included in the next block. Most wallet software however tends to badly overestimate fees and people overpay all the time. The coinbase reward is 0.6XMR, but you sometimes see blocks containing total fees up to 0.025, a significant addition to the reward, while other blocks contain virtually nothing for fees.