We will be travelling Rome-Florence-Venice-Milan-Interlaken-Luzern-Milan by train. We plan to buy a family Swiss pass for our time in Switzerland. On the raileurope website, the shortest route from Milan to Interlaken stops at Spiez. The search allows you to tick if you have a railpass. The fare conditions for that state that this the fare is valid for "Holders of a Pass covering at least one of the countries traveled through, EXCEPT SWISS PASS - Valid only for international sectors". I'm not quite sure which pass is valid here. Italy rail pass? Somebody help please? Should I be buying the Spiez-Interlaken leg separately to use the Swiss pass for that portion of the journey?

We would prefer to ride first class on ES trains to shorten travel time and hopefully avoid any transfers. For the Italy part of the trip, I have yet to do all math but I know that Italy railpasses are not generally suggested here. However, point to point tickets on ES trains are ridiculously expensive. Should I consider buying the Italy railpass in this case?

Should I be buying the Spiez-Interlaken leg separately to use the Swiss pass for that portion of the journey?>

No you have misinformation - your Swiss Pass will cover you in full to Interlaken from the Swiss-Italian border - you simply buy a Milan-Brig ticket for the Italian portion then your Swiss pass kicks in.

I am 100% sure of this.

Thanks. I've just looked at that route. Milan-Brig-Interlaken still stops at Spiez before proceeding to Interlaken. Do all of these require train changes - raileurope does not exactly say? If so, I would still prefer to do the most direct route (i.e. only one stop at Spiez).

Tea you always must change at Spiez to get to Interlaken if coming from the south - a simple change, believe me!

Thanks Pal, I always believe you and rely on your expertise.

I assume there will be no train changes in Brig too? And coming back from Luzern - how do I make the most out of my Swiss pass? Raileurope is giving me this Luzern-Arth Goldau-Milan.

Okay so I've done my math for Italy and hopefully it's correct. For those who are interested: using first class flexi point to point tix, raileurope(sg) is 20% more expensive than trenitalia because I can use the family pass on 2 routes. Without the family pass, the cost is actually roughly the same. With an Italy pass on raileurope, tickets are 50% more expensive than just getting point-to-point tix in trenitalia (with the family pass), 25% more without the family pass on trenitalia.

I assume there will be no train changes in Brig too? And coming back from Luzern - how do I make the most out of my Swiss pass? Raileurope is giving me this Luzern-Arth Goldau-Milan.>

well a few years back you would have rarely had to change at Brig but since the Italian Railways for some weird reason severely limited cross-border trains you may well have to change in Brig/Visp as well though there are still some direct Milan-Spiez trains so point for those.

From Lucerne yes you go over to Arth-Goldau, a stop on the Zurich-Lugano-Milan Gotthard route mainline - there are i believe some direct Lucerne to Lugano trains but no Lucerne direct to Milan trains i believe. You simply use your Swiss Pass to get to Lugano or actually the border point Chiasso a few miles south of Lugano - having before boarded the train in Lucerne bought a Chiasso-Milan ticket so no need to get off the train if it is one that continues across the border -on some services you may have to change at Lugano as well. Changes in Switzerland are orderly and Arth-Goldau and Lugano are stations with only a few platforms.
Raileurope is giving me this Luzern-Arth Goldau-Milan - corrrect but the border point is Chiasso. It is hard to get answers off RailEurope.com - if you want to talk to someone who knows everything then call Byron at www.budgeteuropetravel.com - i have bought passes from him for years and even if you have already bought a Swiss Pass i am sure he will patiently IME answer any questions. I will try as well but sometimes talking to an expert is so nice.