It was a good experience although one doesn't really see the monks or gain insight into their life. One person checked us in and showed us to our room, in which our food was already set out waiting for us, and we saw a monk the next morning conducting a prayer ceremony - that was it. The prayer ceremony itself is something to observe, rather than a group meditation sitting, and all in Japanese.
Be aware that Saimonin has a 9pm curfew, and the doors to the temple only open at approx 7:30am the next morning. We wanted to see the cemetery in the misty dawn light, but couldn't leave the temple until the sun was already fully up. Also, the shower facilities are only available to use between 5-9pm on an evening, although there are communal washbasins and toilets available.
This is a simple, more austere place, there are no tours or classes, like in other temples. I had the impression that the people who worked there, whilst polite, did not necessarily enjoy dealing with the guests.