As I stated in your other post, basing a program's merit on the size of the download comes off as incredibly stupid. No offense.
There are usually 2 compression/extraction levels involved when it comes to downloading and installing software, and that's the reason for the small file size. And besides, would you really want to download something that's over 100MB in it's uncompressed form?
As for Sound Forge itself, it's a very good and very stable program.
Before SF, I tried and used no less than 3 other editors, and none of them was close to SF in matters of features and stability.
By the way, I also use CD Architect 5.0, and ACID Pro 4.0, and have no complaints about either of them.
As for the price, that's the ONE thing I have against Sonic Foundry/Sony.
They're products are very good, but they're also overpriced.
It's the "Adobe" syndrome... overpricing your product based solely on your name, and your customer base. A perfect example of this are the noise reduction plug-ins that Sony sells. I use a full blown audio restoration program that does infinitely more, but for a lot less. And so on and so on.
You might want to consider the scaled down Sound Forge Studio. It's a lot less money, and it's more than capable of doing basic editing. Before my jump to SF 7.0, I had used SF Studio for over a year.
And finally, shop around for prices; including your local music shops. The Sony website's prices are high more often than not. I got ACID for $100 less than what the Sony site advertises, and SF for $50 less.
Best of luck with whatever decision you make.