Pro-ject speedbox: Is improvement worth the $ ?

I had an MM7 for a few years, and when I added the Speedbox I noticed immediately the improvment in image stability and pace. Do yourself a favor and add this essential piece of gear to your MM table.

I saw a difference with my Project Xpression, more bass

Not really, Brf said it best. You will be better off putting the money on a better cart.

Hmmm. The table will be plugged into a voltage regulator so it WILL see a steady 120V. All of my equipment draws such little power the output always shows 120V in the display, never going up or down even one volt so I should be good there. Like Kiko said, think I'll just upgrade the cart for now...... and maybe a cork mat. Was going to get the acrilic platter but am having a hard time justifying the price for a platter at 1/3rd the cost of the table. I'd rather get a cart. Maybe an Ortofon Blue.....? I have a Graham Slee coming so if a put a nice cart on the table it may be a decent analog setup.
Thanks to everyone for your opinions so far.

Which Graham Slee are you getting Devilboy? We may be able to recommend a cart based on the Slee's specs.