Thus far, I haven't ever had any problems running a bunch of Sonnox Oxford Dynamic LEs at a time. I am running the plug-in on a Mac Book Pro that has a 2.2 Ghz Intel Core 2 Duo processor and 4 GB of RAM and within this configuration it runs quite well. I run the plug-in in Pro Tools LE 7.4 that runs off of a Digi 002R audio interface. I can't complain at all as I am able to run as many of these at a time as I would like, but this really depends on what type of system you are running it with. This being said, as long as you have a pretty good system and a good sequencer, I can't imagine that you would have too much trouble running a lot of these in a single session.
I've only had the Sonnox Oxford Dynamic LE for about six months but it has been a very welcome addition to my set up as it gives me another dynamic processor to mess around with. It works great on just about any application as it has a really clean sound quality. However, I tend to use it mostly for acoustic guitar and for other lighter instruments that I want to compress as for whatever reason it seems to work best for this use. The price doesn't make the Sonnox Oxford Dynamic LE the best deal in town, but it isn't overly expensive. Whether you are a home studo owner or a professional, the Sonnox Oxford Dyanmic LE is worth looking into.