FWIW, SSD actually reduces your Windows Experience Index. I'm using a Samsung 840 Pro SSD (one of the faster ones out there) and my WEI is 7.7. There is probably clean-up maintenance work I could do on my SSD drive to improve that a tick.
Having said that, WEI isn't a good benchmark for SSD drives. Some good ones are ATTO, CrystalDiskMark, and HD Tune. ATTO's benchmarks show the Samsung 840 is near the top of the line.
I boot into one SSD drive, and use a 2nd internal SSD drive for all my VMs (one for Win Server 2012/SP2013/SQL2012, another for Win Server 2008, SP 2010, etc)
It has taken me years to build development and demo environments that I was happy with. I've booted into a VM with SharePoint 2013 using SSD and then a standard 7200 rpm drive....holy cow, what a difference SSD makes.
Related topic: SQL 2014 has a new Buffer Pool Extension that targets SSD drives. Heavy OLTP environments stand to potentially gain big-time from this.
