Since I play bass and also sing lead my ideal drummer is THE ONE I MOSTLY DON'T NOTICE. If I'm not worried about following a sloppy drummer, well, that's the indication he does a good job. Had a horrid 3 years in what I call MY band with a guy who couldn't play. I accepted him joining altho' I hated the guy's sloppy playing (and his nonexistent implication with the band) because it was backed by my partner in the band (guitarist, we co-lead, compose most of the material and are the only stable members since the begining). I had respect for his choice but was HAPPY AF when the guy left in 2014 and we got ourselves a real drummer. I wasn't able to reach full potential as a singer as I was always forced to pay attention to him playing out of tempo/groove/sucking a lot. It affected me to the point I wasn't enjoying it at all, was about to stop playing bass, hire a guy to do so and center myself in just singing. Once the new drummer showed up (all of us had previously played with him in other projects) nobody talked about hiring a bassist ever again, I recovered my love for playing bass and singing first rehearsal, second f*ing song. I hate sloppy drummers. But I hate sloppy drummers who don't admit their slop more (very common too). Tempo (and to an extent groove also), as pitch, is a psycho-motor condition, either you have it or not, not too much grey in between, pretty much binary, learn to identify them and don't waste your time with worthless drummers. As for me, not a grooveles/timeless drummer ever again in my life.