Greenboy and Supertanker-
Can't wait until one of you two pop in the 3015LF and tell us how it sounds!
Carvin's shipped price on a PS15 is just at $90, and they don't go for that on eBay, but I expect a nearly-new one would sell for $50 or 55, so that does offset the purchase of a 3015LF somewhat.
Carvin gives nearly no information about the PS15 driver on
the product page, other than to say "Power: 400 watts. Freq. Response: 38-3.5k, 8 ohms. 10 lb. magnet structure."
Comparing the same info on the 3015LF: 450 watts RMS, 900 program, frequency response 40 Hz-1.5 kHz, 8 ohms, and total (net) weight 8.6 pounds.
The 3015LF handles similar to more power, depending on how Carvin rates their woofers. Similar frequency response below the probably midrange crossover point, however, I'd personally put more stock in the 3015LF rating in THIS cabinet, the 1503. Same impedence, so the 3015LF will work fine with the stock 1503 crossover.
A big difference is the weight! Just the magnet on the PS15 weighs 10 pounds, for a probable total driver weight of 15-18 pounds, while the 3015LF's total weight is 8.6 pounds.
Assuming the PS15 DOES weigh 18 pounds, then the difference in the driver weight will drop the total 1503 enclosure weight from 58 pounds to 48 pounds.
48 pounds is not comparable to the ultralight cabs on the market in 2007, but it's not a heavy carry and stack at all, especially with the 1503's nice recessed handles.