Comments on converting YOUR web site to SSL:
1. it slows down your delivery to both the punter AND to bots; so googlebot will take longer to process your site - will google worry? - and speed reports from browser tools will show a much slower page delivery. So all you guys who are trying to speed up your site to reduce googlebot's access time...
2. you will need a faster web server with higher bandwidth: there is quite a bit of extra data sent in SSL mode. And remember you will have to deliver your images in SSL as well because browsers are usually set to report mixed-source content, which will tend to turn punters away from your site.
3. it is feasible that not all bots are able to read SSL data anyway. Some of these bots may be amongst your stable of "permitted" bots.