Not sure for what application you are going to use it but I have used them for years for my fly in trips to Canada. I have had several and think most come in the 1w/5w power configuration. The only feature I can tell you that is an absolute must is the water proof one. My first unit was a Humminbird and it's water proofing was a plastic custom bag.......worked but what a pain! I have been very happy with my uniden Atlantis 250 unit. It comes with both a rechargeable battery pack and another which takes batteries. Our primary application is to keep the boats in communication with each other so we can split up and cover more water at one time. They also serve as a major safety factor up North if someone gets in trouble, breaks down or lol gets lost ( oh what a story ).
If you are always going to have access to electricity the extra battery pack option for using I think they are AA may not be necessary but still nice to have the flexibility if you go to fly ins with only low voltage solar lighting. FWIW a set of regular batteries usually lasts us 3 or more days being on 8+ hours constantly a day.
I am sure someone with more technical knowledge can help you more but thought I would add my two cents.
I tried a Raymarine handheld one a few years ago. A couple of us took them on a trip to Lake Vermilion in MN and they were crap. Basically their range on the water was terrible. When we got home, I returned it & bought a Standard Eclipse that mounts under the dash. I was concerned about an 8 foot antenna on a 16 foot boat so I went with a 3 foot stainless whip antenna, mounted on a ratchet base, that allows me to fold it down when necessary. The whole setup works great. I've talked to guys more than 10 miles away and the weather alerts have come in really handy on more than one occasion. To the best of my knowledge, the most you'll get in any handheld is 5 watts...versus 25 watts with a permanent mount. Then theres always the issue of batteries with a handheld versus the permanent mount thats powered by the boat's electrical system. For the money...if you have somewhere in your boat to mount it, go with a permanent mount rather than a handheld...you won't be disappointed.
I bought a Uniden Mystic a few years ago, a radio/gps combo which comes in handy. It has all the normal radio features and comes with mapping software for the gps. Even though I now have separate radio and gps units on the boat, I've kept it and still use it. The gps works good for ice fishing too. 2
Don't expect too much out of a hand held. They are meant for activity around a marina. You'll get your weather band info, but you won't get much range. Especially, if you are using it on the Illinois River. All these radios are line of sight. Trees and stuff get in the way and reduce your range. You'll hear people better than they will hear you when you use a handheld. So, if you intend on talking to folks farther than a mile or two, you'll be happier with a grown up radio.
Here is a point. I have two radios with 8 foot antennas. I used to have one radio with a three foot bass boat antenna. I could hear, but they could not hear me very far away. I switched to the eight footers. My buddy currently has a grown up radio with a three foot antenna. Five to ten miles away on open water and he can hear me clear as a bell, but i can bearly hear him if at all sometimes within one to two miles away. He is also garbled, but that is a separate issue.
You can get the hand held, but i recommend the grown up radio and an 8 foot antenna on a swivel mount. (so you can lower it)
I also recommend for those with grown up radios to solder the braided wire to the connector if you are having problems with garble. The compression connectors don't work that well all the time. Also, you should run a separate battery pair from the battery to the radio to eliminate engine noise when you talk plus it eliminates blacking out your depth finder and FM interference when you talk. I don't understand why it works, but it does.