I went to a St. Louis Blues hockey game last night. I wondered how much their sticks or skates cost. It occurred to me that their sticks and skates may be $400 each. It also occurred to me that I would be equally useless with a $400 hockey stick as I would with a $4 hockey stick.

So even if compressor plugins aren't 100% equal to the best hardware compressors, there are some serious advantages to using plugins. Price, quantity, and sound all come to mind.

Price – Hardware compressors range from $100 up to $4,000 (and probably higher than that). It's rare to see a compressor plugin that costs more than $1,000. There are some great free compressors plugins out there.

Quantity – I can't afford to buy 20 $1,000 compressors. However, if a mix calls for me using 20 compressors, I can use the same compressor plugin 20 times.

Sound – Have you ever stopped to wonder why there are SOOOOO many compressor models? The answer is simple. They sound different! Some work better for different things. Of course, the opposite is true. Some sound worse on different things. Typically, hardware compressors are going to have a specific character to them. In many cases this character will be a positive thing, but there are always times when it will be a bad thing. So, what happens if you save your pennies to buy a high end hardware compressor and then find out that you aren't thrilled with what it is doing to the signal.

While not a high end compressor, I tried out a Presonus ACP 88 a while back. I must say that I was WAYYY happier with my Waves Rcomp for vocal compression.

So, I think a person can not expect one compressor to be perfect all the time. Plus, I think if you are on a budget a software compressor may even sound better than a hardware compressor.

Last, but not least, don't forget that it is very simple in a program like Cubase to use a compressor plugin only on the monitoring end while tracking. In other words, you can put a compressor on a singer while they are tracking and then turn it off, remove it, or use a different compressor later. This is all done without the need for a mixer.

Conclusion
Unless you are a badass at recording, you don't have any need for a hardware compressor. The big boys use plugin compressors all the time even if they sometimes prefer a high end hardware compressor for this or that.

Brandon