784 Danforth Terrace is 31 yrs old; the HOA fees is $325 per month (according to the MLS) Carlisle Way HOA is $275 which includes water, among many other items; make sure you find out how much the HOA fees are where ever you decide to purchase your home.
The $600K price range is on the high side for condos in Sunnyvale. Most tend to be $550K and below, although there are a few high end complexes that get above $700K. At $630K, it would be nice if it had a garage. Also, a $30K premium for a larger patio & storage room is a bit expensive. That being said, however, it's a good complex and you should do well.
I'm not sure what your requirements are, but there is another unit that just came on the market today. It's at 784 Danforth, priced at $549,950. It's more of a house style unit with vaulted ceilings, located across from a park. There are quite a few condos in the mid $500K range, but for the most part, they aren't updated to the extent that Carlsile Way is. I can send you some ino if you are interested.
I hope this helps.
In looking at the MLS, there are two units currently for sale in the complex. One at 865 Carlisle Way, the other at 857. Both are 2BR, 2 1/2 BA units being offered at $599K. The quality of construction looks very good! I'm not sure where the $630K price comes from, unless it's a larger unit or has some other ammenities.
The sales literature does not list square footage, so it's a bit difficult to compare with other condos that have recently sold in the area. With them being newer, Carslile does appear to be nicer that most of the other units that have sold in the same price range. I would guess that they're a touch smaller, however.
If you can tell me how many square feet the unit you are looking at has, I can give you a better analysis.