Author: Window4U (IL) (---.client.insightBB.com)
Except for the presevation comment I added at the end, this list is taken verbatum from Alsides website. They are listed in order of quality and price, starting at the lowest quality;
1. * Centurion® Premium Vinyl Windows
This classic beauty designed for superior comfort features butt-joint reinforced corner construction and aluminum reinforced sashes for strength and stability.
2. * Geneva™ Welded Sash Vinyl Windows
The elegant looks of this window come from its slimline design. The increased glass area means maximum views, while fusion-welded sashes provide years of trouble-free operation.
3. * Excalibur® Fusion Welded Vinyl Windows
For superior strength you can't go wrong with Excalibur's fusion-welded construction. The beveled frame and sash design is exceptionally slim and refined so your home will shine in a whole new light-inside and out.
4. * UltraMaxx® Fusion Welded Vinyl Windows
Maximum strength for ultimate comfort is the hallmark of UltraMaxx. Extra thick vinyl extrusions provide ultimate welding strength to fusion welded frames and sashes. And UltraMaxx is available in light oak, dark oak and cherry woodgrain interior finishes.
5. * Sheffield® Fusion Welded Vinyl Windows
Using advanced design and superior materials, Sheffield Windows produce outstanding energy savings and trouble-free operation.
6. * Preservation is the best in the Alside line and is only sold to exclusive dealers.
With 5 other window lines above the Centurion, and 3 above the Excaliber, just be aware you are not getting anywhere near a top of the line product. The Centurions are the same window I installed for Alside back in 1984. Not exactly state of the art technology.