The first time I left my 9mo son for 10 days (with my DOTING parents) I was a nutcase for the first few days, and then (with the addition of sleep, daily calls & reports, etc) I relaxed into things, and by the end of the 10 days I didn't really want to go back. (just for the record I *did* go back).
He had a splendid time, I had a splendid time. First day or two was a bit of transition, and then everything was back to normal. Ever since then I haven't felt any guilt for leaving him with loved ones.
I love him so much it's dizzying, but if anything, those little mini-breaks are a thing that I look forward to.
Of course, as he got older, we get to talk on the phone... which is SUPER enlightenting. About 1/2 the time kiddo is way too busy with something "interesting" to talk (It's just mom, I'll talk to her later...LOL), and the other 1/2 of the time it's "Mommy!!! Guess what nana & *I* DID!?!?!"
My kiddo has always been extremely well "attached", meaning he has total trust that I'll return... whether it's an hour or a week.
He also has a KILLER relationship with my parents. The watched him for about 1/2 of my travels when he was little (I brought him with me the other 1/2... and now 100% of the time... we're about to head off to argentina for a month), watched him while I was in school, and today watch him one afternoon a week (it's their playdate), and one night a month. He's one of those very charismatic, so sure that everyone loves him that they do, kind of kids.
I never feel guilty for leaving him with my parents or anyone else who loves him. I feel happy for him, and happy for me. ((And NO ONE could accuse me of being distant or insensitive... I'm one of those very emotive/excited about life and sharing it kinds of people. I'm also a SAHM / WAHM, Homeschooler, etc... I LOVE being around my ds7. But I'm also happy for his adventures, and happy for my own)).