Solid State drive vs. traditional hard disk in a virtual server environment

I am currently considering upgrading my virtual-hosting plan because of very bad write performance (mostly writing to a MySQL database, but I notice it also when compiling a program or copying files - or any other write operation). At some times (probably when many other customers on other vhosts are using the hard-drive) a write can take up to several dozens(!) of seconds, even when it's a small write operation, which is unacceptable. Read performance is much better, probably because of good caching (in fact when we start using the database at the morning each day, we notice how slow it is at first which would suggest that the cache is being filled - but that is OK with us). I don't know the specifics of how the hard-drive is used and prioritized in a Linux/vhost environment, but I can imagine that a lot of time is lost by jumping between vhost-partitions. On the other hand, it may also be possible that an SSD pretty much behaves like an HDD (only a bit faster, which would not be enough for me - 20 instead of 30 seconds is still unacceptable) from the user's point of view. Does anybody have experience with both HDDs and SSDs in an vhost-environment? Is there a different "character" (regarding relative speeds of reads and writes and especially latency) noticeable as a user? How is the hard-drive prioritized and in which ways does an SSD make a difference, especially on a overloaded vhost-system? Do you think that changing to an SSD can prevent this extremely bad write-performance spikes?