I've always played with a 59" and I always get it with a 30" shaft... I think it balances the bigger cue nicely in the hands... Plus if you need to sell it someone can down size a shaft easier than the butt lol... Just my opinion
You get the advantage of length with the 30 inch shaft and, if you tire of the cue, anyone can replace the current shaft with one that is 29 inches. So, resale is easier.