Now, I'm a far from an expert, but I feel, that it is equal. Someone with experience, please correct me if I'm wrong. It appears to center around the antenna, as you can make LEO (Low Earth Orbiting) satellite contacts, on just 5 watts, from a handheld. More watts out, will greatly help your chance of hitting the satellite, but there are several articles floating around, and tons of Youtube videos to watch, on people making multiple contacts with a handheld transceiver.
What do they all have in common though? That Arrow II antenna, or a homebrew version of it. I was using a Diamond rubber whip antenna, and I was picking it up just fine, but I got lost in the dogpile of people trying to make QSL's..I am going to construct my own antenna, or buy that Arrow II, in a few months, and try again.
A base station, which usually yields more watts out, with a dedicated/mounted antenna, would have a better chance of being heard into the satellite, in comparison to a 5 watt handheld, and an antenna like I was using. But, the equality I am talking about, comes from the outcome for both. You make a contact (provided, your handheld has a decent antenna).
I like running a handheld/portable, because 1.) I get to go outside, and do it, and 2) I like it when the younger kids in the neighborhood come up, see the equipment, and ask what I am doing. I get to tell them, I am attempting to make contact with other people, using a satellite in space. They stand around, and listen. They get jazzed when they hear the satellite communications break through the squelch, and what have I done there? I planted the seed of scanning/ham radio in someone else's mind.. Win / win
That's it for me...
~Brian