Fran, you say it's not good to drop your elbow "to avoid the downward finish", but then you say you sometimes drop your elbow "to keep the cue level after impact". What's the difference? Am I misreading this?
Yes, I think you are. When I drop my elbow, it's a true piston stroke that drops before impact. That was Robin who said he drops it after impact to keep it level. My suggestion was for him not to do that because it could result in poor stroke timing and double-stroking the shot. I think it's best to totally commit to one stroke or the other for any given shot. I use whatever stroke I feel works best for a particular shot but I commit entirely to that stroke.