I bought the SE K510i in July, 2007. I bought this phone for my dad, whose only requirements were a large address book and bluetooth support.
When I started looking for affordable BT phones, I was shocked to see that there were almost none below my budget of Rs 8000. My choices were limited to:
1) SE K320i(4, 800)
2) SE K510i(5, 100)
3) Samsung E250(6, 800)
4) Nokia 3110 Classic(7, 000)
N-3110 was eliminated right away since I already had one and didnt want any confusion with 2 identical mobiles at home. Samsung E250 has pathetic battery life. SE K320i was too much of a compromise for Rs 300, and I ended up going in for SE K510i.
The sales package included a data cable and software CD, but no handsfree set.
The phone retains the "classic" K-Series look and is very similar in construction to the K310/320i. I believe this phone is merely an enhancement of the K310i platform. I looks decent enough, but somehow has a certain cheap look about it.
The keys are made of soft rubber. The keys are not very resposive and require you to press hard. Although the keys are well spaced out, due to their really small size, hunt and peck typing becomes inevitable. The keys are bunched together at the bottom which makes the phone slightly unbalanced in your hand when using it. Backlighting of keys is sufficient, but is by no means uniform. SE has chosen a green backlight for the keys which makes the phone look even more cheaper.(I have always associated green backlights with ultra-low end phones)
The joystick itself is quite nice to use. Some(like my dad) find it a tad too responsive.
While the display at 128x160(262k colors) looks good on paper, it pales before displays from Nokia and Samsung with identical specs. It’s somehow not as bright/vibrant as other similar displays. The display remains somewhat readable under bright sunlight.
Signal strength was(subjectively) better than my Nokia 3110. In-Call and ring tone volume is a little low and might be a problem in noisy environments.
As the phone doesnt have dedicated volume keys, you have to use the joystick to change the incall volume during a call. This is mighty inconvenient and the fiddly joystick makes it worse. The speakerphone too is a bit on the softer side. As the speaker is located on the backpanel, it’s sound is diminished when placed on a table.
The camera seems pretty decent, but at 1.3MP, without flash or autofocus it’s nothing more than a toy.
The phone doesnt have expandable memory and so the included media player is not of much consequence. SE has however, provided a relatively generous 28MB of on board memory.
Subjectively, I felt that java applications took a little longer to load than comparable phones such as N-3110. This could be due to the age of the underlying platform.
The phonebook can store upto 1000 contacts, which should be more than enough for anyone. It does have a few quirks though - Groups cannot have more than 20 contacts. Extended contact info such as home/office/email etc is visible only in the "edit contact" screen and is not easily accessible. Quite a pain when you need quick access to a contact’s alternate phone numbers.
Battery life is average - it lasts for about 1.5-2 days with 1.5 hrs of talktime per day. If you gab a lot, I suggest you buy a spare charger. The phone also charges(albeit slowly) when connected to the comp with a data cable.
All in all, this is a great phone for the price.