Your question is one that will promt great discussion. That being said, there are many realtors, such as Terry Yimin, who answered your question earlier, Karen Wilso, of Caldwell Bankers, Myself, and others who truly understand theTierra Verde / Isla del Sol Market. Especially when it revolves around Investing or covering the Debt Service of a condo until you wish to move in, if that is your desire.
As to the condos in that area being a sound investment. Please keep in mind that what is a sound investment to one may not be to another. Consider what you are looking for in a return. Consider the area. Consider the costs. Then give very careful consideration to working with someone who has a financial background and works with investors, such as yourself.
The whole area of your interest provides a variety of investment opportunities. But, whatever your needs are, the most sound opportunities will be in those units offering 7 days or less rentals, and where the monthly association fees are the lowest, as shlould be the case with taxes and insurance.
Yes, some of those complexes were built in the 70's and some in the mid to late 80's and on, but that doesn't necessarilly detract from the value that you want to receive.
As for whether a 1 bedroom 11/2 bath is better over that of a 1/1 . . . I would look to those offering 2 bedrooms and 2 baths, as they will provide a broader spectrum of the market for renting and for future resale.
Good luck in your venture, and if I can be of any assiatance please feel free to call. You may even wish to visit my website. You can click on the agents bio and get a feeling for our experience.