Opinions vary, depending on your immediate need. PSCFG does many things, thus the name "PC SALES GUIDE/Configurator". Probably the most powerful feature is Needs Assist. It seems to be unique, in that you can take a series of customer requirements, plug them into Needs Assist, and PSCFG will locate all matching systems in a few seconds. There are approx. 35 different categories of Needs, not all of which are relevant to every system. For example, Notebook Weight is not relevant to Servers, and number of Hot Plug Bays, if applied to Desktops, would equally find no matches. Others might seem to be obscure, but are not. Maximum Memory is the value for the most memory you can install in a system. This might seem a minor issue, but if your customer requires a system get to 6 GB, perhaps later, there is no need to propose a model with an upper limit of only 4 GB. Setting this Need as "6 GB/Minimum" strips out all the models than don't make the cut. Filtering such models out of a list of possible candidates can take a lot of time, unless you have something like Needs Assist, given that for the U.S. alone, in Feb/2013 there are some 1,500 current notebook models alone, spread across three families - ThinkPads, IdeaPads, and SL/Edge models. Finding not just one model matching your requirements, but finding all of them, is a time saver of significant value.
The benefit with Needs Assist is that it searches multiple product "silos" in a single pass. This is possible because all the product specs are arranged in a database. Tools like the PSREF and OCM are documents, and while you can search them for instances of a text string or partnumber, they don't lend themselves to commands like "Find All". The Needs Assist function handles that cleanly, as well as doing multiple searches in a single pass.
Needs Assist operates by 'building' - in memory - all the system units within the family or families you have selected. It starts with the basic chassis/cabinet, then populates each model with all the standard components, and comparing the resulting model with your list of Needs. If a system does not match all your Needs, it is discarded and 'building' other models continues. If it matches all your needs, it holds that model in memory, and continues building the remaining systems in the families you selected, until it has completed all of them. Any hits are displayed in the Results panel, complete with the partnumber, one-line description, and any price/supply values. Each of them can be expanded by using the Show Details feature, so you can compare individual features in the extended descriptions, one system against another, or against many.
Sometimes you will get no hits. In cases like this, you may choose to adjust your Needs values slightly. Suppose you chose a Base Memory of 4 GB/Exact Match and got no hits. Try changing it to 4GB/Minimum, and you may well find there are multiple hits that come with 6 GB standard. Or, suppose you selected TopSeller as a Need, and got no hits. Press Reset to delete this one Need, and you may find matching models that are not TopSellers.
Sometimes you will get too many hits to manage easily. Again, adjust some of the Needs up or down as appropriate. Try setting a Maximum price, to see if that will help reduce the number of hits.
One final point is of particular benefit to Business Partners. Suppose the customer requirements find no matches in the current models. But there may be a matching model which was withdrawn recently. When Lenovo withdraws a system unit, it will be moved from the current model PSREF file, to the withdrawn models file. Just because Lenovo no longer markets that model, does not mean a Business Partner may not have one or two on the shelf, looking for a home with a customer. Searching Withdrawn Systems may find such systems. This is another value to showing both price & supply on the same screen, when making selections from a multiple choice menu.