You asked for my opinion so...
I hated the v4. Hated it. I preferred the v1 over it and I even preferred the v5 over it, though I must say, the v5 got quite boring after a few generations.
Why did I hate it? For lots of reasons.
First of all, you know how you have to raise skill points for jobs and stuff? Well, the v4's lifespan happened to be shorter than previous Tamagotchi because they evolved sooner. Apparently the Entama and Uratama's lifespan was longer, which is good considering how involved this Tamagotchi is. I guess jobs didn't require that many skill points though and it took fewer skill points to get a secret character on the v4 (450 with at least 350 in a certain stat) than on the Entama (999 in a certain stat). It only takes around 80 skill points to get a job on the v4 though once I heard that someone had no skill points and they got a job!
It feels like you're more pressured to play games on the v4, which is so annoying seeing as the games are just... plain long and annoying, in my opinion. Plus you may have to feed your Tamagotchi snacks, just to be able to play a game. When I was aiming for secret characters, my Tamagotchi got numerous toothaches. I timed the games once.
Jumping Rope- 1min 50sec
Mimic- 3min
Shape- 1min 30sec
Dance- 2min 30sec
Flag- 1min 40sec
And you have to play the games all the way through to lose the maximum amount of weight for that game. On my v1, it took me around 30 seconds or less, either doing one round of Dance or three hurdles in Jump. In Jump, I could lose 3g of weight and for Dance I could lose 2g (I only needed to be 2g above base weight to play this one). Me, being the perfectionist, always likes my Tamagotchi to be at base weight. So if my Tamagotchi is 3g above base weight and I play a game and nearly complete it, my Tamagotchi only loses 2g of weight and I get so frustrated sometimes. Sometimes I can blame losing on being terribly bored with the games or the buttons of my v4 being stiff. Yes, my v1's A button has been slightly rusted on the inside due to my idiotic running through sprinklers once (I didn't actually have a choice at the time) and most people consider the games even more boring, but at least I don't have to play them the whole way through!
Mail irritated me. It irritated me how you could get poop and stuff in the mail which made your Tamagotchi upset and empty all of its happiness hearts and then you'd have to go through the process of feeding your Tamagotchi snacks and then playing one of those games! It often felt like I got negative things more than nice things which made me refuse to open mail altogether. I didn't mind the important mail or even the fortune mail as much though because they didn't come as often and didn't make as much of an impact on your Tamagotchi's happiness. What I don't like, though, is that Bandai failed to explain the important mail properly in the manual. Most people got very confused when it came to job offering. I was alright because I had Tamatalk, Tama-Zone and some other Tamagotchi sites, but what about all of the people who didn't?
I encountered a couple of glitches in this one, the name glitch and the ball glitch but they didn't really worry me, not even the ball glitch because that was one I triggered myself. As long as you take care not to delete lots of items at one time (another thing that I don't think Bandai mentioned in the instructions is how to even delete items in the first place!) you should be fine. For the name glitch you just need to reset and download (calling it "download" can be misleading- my friend's dad thought it meant downloading photos off the Internet!) and it should be fine then.
Another thing I dislike about the v4 is how you can decide which character you want and then get that character. The only problem is that the "family" your Tamagotchi is in is random, unlike the En/Uratama (first generation is random, then depending who your Tamagotchi mates determines the family of the child), which could have been a good thing if only the v4 hadn't seemed so geared towards giving me the Meme family far more often than the Mame or Kuchi families. On the v1, it depended on what kind of care you gave though I tend to be the type who tends to give their Tamagotchi good care without even thinking about it, or maybe the v1 isn't so fussy, because I was continuously getting Mametchi and Mimitchi with the occasional Kuchipatchi or Memetchi in there. (I always rejoiced when I got something other than a Mametchi or Mimitchi.) Rarely, I'd get a few other characters, though I have never, ever, gotten Hanatchi on my v1. 104 generations and I haven't ever had Hanatchi yet! (Maybe because I'm afraid to starve my Tamagotchi.) Different characters were more common in my first 10 generations when I wasn't that familiar with the clock-stop pause that I had to use on my v1. There are less characters on the v1, but somehow I liked it so much better because it wasn't like the "you-can-pick-what-character-you-want" kind of thing like the v4 and the v5 (especially the v5).
Those are my main gripes about the v4. I think the v4 was too involved, which is why I'm not planning on getting a Music Star any time soon. Now I'll give you a few opinions about the v5.
v5 is good if you don't have much time to care for a Tamagotchi but I personally believe that, like v1, this is a version that you have to raise alongside another Tamagotchi. I raised my v1 and v5 together once, then I took the battery out of my v1 and that's when I started getting bored of my v5 because it didn't feel like I really had to look after a Tamagotchi at all. Sure, I could feed it and give it a few items to make it happy every hour and clean up its poop every two hours, but that was all. I never needed to worry about giving them enough exercise or discipline them, which really sets the v5 apart from the v1. Items on this version just seemed like collectibles and you could just use codes to get all of them anyway. You could really choose what characters you wanted and in around 17 generations I had gotten every single character and every single family, including bad care families, at least once, while on my v1, as I said earlier, I'd raised 104 generations and didn't ever get Hanatchi or Otokitchi (though I guess I could get Otokitchi any time I wanted, as long as I had a female Tamagotchi and it would be good to have my an Ojitchi on my v4 so I could have them mate any time I wanted them to).
