Obviously, you would not be replacing your windows with frames and panes that are even worse. You should always pick windows that are better in every way. Consider windows with at least two panes filled with argon in between for better insulation, low-e coating to reflect UV rays and better heat retention, and durable framing materials such as fiberglass and vinyl.
Windows also need to be properly installed in order to work as intended. A single mistake could leave a window full of efficiency problems, rendering any useful features it might have useless. If you feel unsure about your DIY skills, hire a San Jose windows replacement contractor to perform the task. Most replacement window companies offer their own in-house replacement services, so ask around while you shop for a suitable pane or frame.