Features — 10
I'll say this at the outset - expectations from low price amps are really key here. Most of the ratings I gave are because, before buying this, I knew what I wanted out of a practice amp and wasn't expecting anything more than that. It should go without saying that when you're paying $100 for an amp, there will certain compromises you'll have to make compared to more expensive amps - sound, features, etc.
Okay, the review. The Blackstar Fly 3 is a solid state two channel - clean, overdrive - amp. It has gain, volume, EQ, and a built-in delay effect. It also comes with an MP3 input and a headphone/emulated output. I haven't used the output because I only use it for practice, but this amp can be as quiet or as loud as I need for for in-home use. The delay is pretty good, but it wouldn't pass off as elite. The manufacturer doesn't specify the delay timing, but if I were to guess, it goes from something close to 0ms up to 500ms, maybe 750ms. I still love the feature though.
I HIGHLY RECOMMEND getting the extension cab. It adds a fullness to the tone that I just can't get with the amp head alone. In fact, I probably would not recommend this amp if you're only getting the amp head and not the extension cab. For an extra $40, the amp head and cabinet combo is well worth it (the amp head alone is $60, the head/cab combo is $100).
I have a 2002 Made in Mexico Strat with Texas Specials Pickups and I can dial in decent tones for rock and blues. The clean/low gain sounds I get with my strat great while the overdrive tones are average to above average. I've tried using my TDX9S overdrive pedal, but can't really get a good sound with it, probably since it's a solid-state amp. Still, I really like the sound I get for blues applications given the price tag.
I also have a Dean Razorback with Seymour Duncan humbuckers, and the sounds I get with it are great with the overdrive channel. I can get a great range of tones, particularly for hard rock and metal, though it won't get dirty enough for anyone who is looking for playing death metal (which is okay by me, not my bag).
I give the features a 10 for an amp of this class (solid, under $100, practice). Blackstar chose all the right features to include with this amp while keeping this amp affordable for any guitarist.
Sound — 8
I play blues, rock and metal and this amp works good for that. You're not going to get vintage tones and you're not going to get extreme high gain sounds out of this amp. I'm not a country guy, but I don't think this amp is really conducive to that sound either - part of that might be my choice in guitars, though.
The sound is warm, gets pretty good mids, decent highs, but the bass is a bit flat.
I don't think it works very well with pedals - a common complaint with solid state amps. I have a DOD FX80b Compressor, Boss NS-2 Noise Suppressor, TDX9S Overdrive, and a Ditto Looper. The DOD works okay with the amp, but I generally don't use it in lieu of quicker set up times. The TDX9S isn't very responsive and drains the tone, making the NS-2 useless. I haven't tried the looper yet, but if I can amend this review later, I'll let you know.
I give the sound an 8, because while it outperforms other amps in this price range, the shortcomings of this amp are foreseeable. If a particular sound is important to you, I'd recommend testing it out or watching Youtube videos. The sound is great for me, but like any amp, the sound may not be for you and without doing your homework first, you may not get a sound conducive to your playing style.
Reliability & Durability — 8
I woudln't say this thing is built like a tank, but if you're using it for in-home use, you won't have any durability problems. It's strong enough to survive small impacts - i.e. I dropped it from about 2 feet and it was fine - but if you're hard on your equipment, I wouldn't expect it to last repeated beatings or high impact collisions.
I wouldn't use this in a live setting where you need the output, but you could jamming with bandmates that can dial down their output to match yours.
Also, the amp can be powered via outlet or via battery power (6 AA Batteries). On batteries, if you keep it at lower volumes, you can get several hours out of this amp. If you play it at max capacity, the battery life is pretty short.
I give this amp an 8 for reliability and durability because, while this amp shines as a practice amp, you shouldn't expect more from it. It will travel well if you're careful, but you'll either be playing on AC power most of the time or you will run through batteries fast at higher volumes.
Overall Impression — 10
For a $100, you're getting the biggest bang for your buck. I'd recommend this to beginners in particular. In my estimation, you're not going to get better features, tone, or sound for the price. It isn't an amp for any genre of music, but no amp is, and this one is about perfect for me for most the type of music I play. Again, the extension cab is a must.
I'd love for this amp to have an FX loop, but that would obviously drive the price up and then again, it being a solid state amp, might not be a welcome addition in the first place. A small nitpick, but I'm curious as to what it would add, if anything.
If you're looking at some of the other practice amps in this class - Marshall MG10 or MS2, Orange Crush 12, Vox Pathfinder 10 - I'd recommend the Blackstar Fly 3. For the beginner, you're going to get a great range of sound until you can identify the sounds and features you are looking for when you upgrade to a new amp. But even when you do, you will still have a great little practice amp to use for quieter settings that will deliver.