For fast prototyping I have several VMs I use (being able to revert to a snapshot is invaluable for testing). I do have 2 mini's and a MBA that I usually test any final process/config/install on actual hardware. Knock on wood haven't had any issues with not having access to the latest hardware with the deployment process we have in place.
I use VMware Fusion Pro which lets you can do linked clones and is definitely a time saver.
I have an i7 MacBook Air with 8GB RAM and a 512 SSD. It's a pretty capable laptop while still being an Air.
I have spare Macs if for some reason I need to test something physical.
Check out Rich Trouton's talk from this year's JNUC on how he does VM testing with Casper.
Second for Rich's presentation. I've been using parallels but I am requesting a copy of Fusion Pro after seeing some of the neat features available. We use vSphere, and our casper servers are on VMs. Being able to access them directly instead of going into a windows vm to use the vSphere client would benefit me. And the linked clones looks really interesting, potentially saving me a lot of space.
Agreed. I enjoyed Rich's talk on virtualizing his test environment. It makes so much sense, but up until seeing his presentation I was always unclear on the best approach. Not to say that his is the only approach, but it certainly seems to make a lot of sense. I would like to trim my inventory down to only one or two test Macs that I use instead of needing to maintain a stable of test systems.
We have one fusion, one ssd and one hdd iMac.
The main reason for this is because we run dual boot machines and need to test deploying both systems and the partitioning etc gets complicated... The HDD is really just so we can get an idea of how long imaging is likely to take on some of the older hardware around the place.
Admittedly I'm a bit horrible on this one. I have used Parallels simply because that's what we've supported for our users. After thinking through Rich's talk I will also be picking up Fusion Pro. Yet, I really tend to test on any given number of on hand loaners we have in the office (Usually 13" Mid 2012 MacBook Pro's). Assuming I'm not making hardware specific installers of course. Generally I'll line up between 3 and 12 units on my bench depending on what I'm testing so I can test multiple variations at once side by side. This is really useful for netboot, imaging and pre-stage testing with various iterations of installer packages. In my environment, speed of imaging can be critical. For testing various scripts I bet I will be a hell of a lot more efficient using Fusion pro with linked VMs