the Samsung SCH-i730 is kind of big and bulky. It has been out for a while so you may have a hard time trying to find this phone if you do actually decide to get it.
I would say the best bet would be a treo, or if you havent already tried it out, the Motorola Q. The only thing with the Q is the battery life. I found it not so good, having to charge the phone every day. With the blackberries, you are right there are not a lot of customized software for this phone. Or, if you check the verizon site, they have a smart phone flipphone. No qwerty keyboard but has the Mobile MS OS installed. has the PDA software and you can do lots with this phone. It got a "good " rating but this may be another option for you.
I habe been researching smartphones, staying with Verizon. The editors choice for Verizon smartphones was the Blackberry 7130c., with a rating of 8.3. In the review area, the Samsung SCH-i730 was rated the best at 8.3 (review was from 2005) and the Blackberry 7130c was 7.7.
Here is what I am looking for. A PDA cell phone combo so that I only have to carry around one device. On the PDA side, I will mainly use it for address book and some software such as Diet Organizer, games, and etc. Since most likely due to my companies policies, I will be synced with my home computer. I will be traveling, but I do not currently foresee the need to retrieve e-mail, play music, play videos, or use my laptop through the phone. I do want a speaker phone, camera if possible, voice dial if possible, blue tooth, good memory, good phone quality, not a lot of dropped calls because of the phone.
The Samsung SCH-i730 seemed to offer me what I want with all of the other bells and whistles. Palm 700p defintely has the software - found the keys a little small for my fingers. Blackberry does not appear to have as much software available - the keys on the 8130 are nice - the keys on the 7130 are a little small, but not bad - didn't like that one key is for two letters since my fingers are big - but for my primary uses, it is not bad.