If that works for your needs, stick to it. But many people don't use Excel because it gets expensive, can't be used with some plants or doesn't work out with sensitive livestock.
Going the regulator route with a paintball adapter may be $80-$90 up front but it allows you to upgrade to a full-size CO2 cylinder down the road if desired. There's also a ton of resale value in a regulator.
Plus the paintball tank, which is $20. Cost is at least $90. Not worth the effort to me. Cheaper to dose excel, which I make from cidex, daily into my 29G tank