Tamps well
I have a DeLonghi EC155 and the smaller size fits very nicely for tamping. It is able to hold over 50 lbs of pressure with no problem. I used the tamping method from Good Eats, where you put 50lbs of pressure, then twist.

Does what it's supposed to do
I have looked everywhere for a tamper that would fit Saeco Aroma for a sensible price, but 53mm tampers were either too expensive or just unavailable. Although this one doesn't fit properly, the small end of it covers about 90% of the basket. Overall, I'm happy with it. It's a temporary solution. Tamper brand or construction is not a huge variable in the resulting quality of an espresso shot. You might at well use something out of the hardware store as long as it tamps the loose grounds well enough. This is why I am skeptical of tampers that cost 50-100 dollars. If RSVP Terry tamper fits your basket's proportions you should consider it.

good find
how can you rate a tamper? well, it fits in the basket and it tamps down the coffee. I guess Terry's tamper does just that. It was a great price, I mean come on, who's the numbskull who would pay $20 for an item to tamp his grounds?
I was impressed by the fast shipping and great customer service.