It's actually not bad at all, and the mileage from where I live (West Chester) is about the same, though I don't have to dick around on I-95 to get to Reading.
The parking costs half as much ($5 compared to $10, $8 with a Phantoms ticket-plan voucher) and is in a covered garage. The food is better and a little bit cheaper. The instant-replay/info board is much clearer (though, granted, it's a couple of decades newer than the one at the Spectrum, so it should be). Ticket prices are similar ($11-$17 walkup prices for the Royals, $14-19 walkup prices for the Phantoms, with both teams offering specials from time to time). There's no upper deck, so just about all the seats have good views of the ice.
The level of play is one step lower in the ECHL, of course -- not that the AHL is always a display of textbook fundamentals and superlative skills. About the only rule difference I can think of is that touch-ups aren't required for icing calls; the play is whistled dead as soon as the puck crosses the end line. (Oh yeah -- shootouts in overtimes, though I haven't personally seen one.)
The Royals have been around for two years, and finished last both times, which will be a shock for expatriate Phantoms fans like myself (the Phantoms have always been competitive, have won one Calder Cup, and missed the playoffs last year (by one point) for the first time in their history). Royals players get called up to the Manchester Monarchs and then to the Los Angeles Kings, which eliminates the nice feeling of watching Phantoms players develop and then go right next door to the Flyers. Then again, with the way that Clarke has mismanaged the farm system as well as the big club, maybe that's a blessing...
And if you're more Philly-centric and would prefer to go east than west, there are the <a href="http://www.boardwalkbullies.com">Atlantic City Boardwalk Bullies</a> and the <a href="http://www.trentontitans.com">Trenton Titans</a>...