Only the provider is going to know if it makes an improvement. They might get a performance benefit from a switching to SSD drives. But what about providers that have very large hard drive arrays with standard 10,000 RAID drives? There's much more involved to shard disk performance than what type of hard drive is being used in the arrays.
But it's important to know that Disk Drive performance is not nearly as important as the software they provide and support, the CPUs and memory. The modules you listed above will provide users with a snappy Drupal site, but not all hosts support them so that is much more important.
Tips on Choosing Suitable Drupal Hosting Providers
Prices of SSD have gone down, and it makes good business sense to use them, but it's not going to be a big improvement in Drupal performance.
Varnish and APC however are wonderful ways of improving performance.