Head to head

Five configurations are in real contention, and print quality separates none of them. All five lay down an accurate bracket in polyethylene terephthalate glycol (PETG). They separate on how much of each record was measured, on how open the machine is, and on whether the chamber is heated or only closed.

The magazine used to be where this chapter turned, and it no longer is. Bambu Lab's own specification excludes any filament containing carbon fiber (CF) or glass fiber (GF) from every Automatic Material System (AMS) unit it sells, the AMS 2 Pro included, so acrylonitrile butadiene styrene reinforced with glass fiber, ABS-GF, feeds from an external spool or a single-slot AMS HT at $139. Read as a routine material that mattered enormously and the AMS scored 4.5. Rob ruled on 2026-09-08 that ABS-GF is occasional, and on an occasional material the same fact is a workaround. The AMS 2 Pro is now scored for what it is the rest of the time: four sealed slots chaining to four units, 65 °C active drying, radio-frequency identification (RFID) that fills the slicer in without typing, live humidity in three places. That is 7.0 against the QIDI Box's 7.5, where it was 4.5 against 7.5 a day earlier.

The QIDI Box keeps the lead on the magazine for a reason that has nothing to do with the reframe: its supported list is the widest here and it dries at 65 °C while printing, which owners say the AMS 2 Pro cannot.

Chambers come next. ABS warps harder than acrylonitrile styrene acrylate (ASA) and wants heat held around it, not just walls. Both QIDIs and the Bambu X2D heat the chamber to 65 °C with high-efficiency particulate air (HEPA) plus carbon filtration; the P2S and P1S are enclosed but passive. Field record cuts the other way: three years for the P1S against three months for the Plus5.

Why the 7.5 on reliability now wins

The P2S Combo with its exhaust kit scores 7.5 on "it just works" against 4.0 for the QIDI Q2 Combo, and it now wins on that strength rather than losing in spite of it, 7.240 to 7.085. The arithmetic, in points of the final score out of 10: for the P2S, reliability at plus 3.5 on weight 25 is worth 0.875, noise and fumes 0.125, value 0.075, software 0.015, or 1.09 in all. Against it, openness at minus 4.4 on weight 15 costs 0.66, the magazine at minus 0.5 on weight 15 costs 0.075, materials today 0.09, upgrade path 0.11, or 0.935. Net margin: 0.155.

Two things follow, and they are the same two as before with the signs flipped. Openness alone still does most of the lifting on the QIDI side, and Rob has said plainly that "it just works" outweighs openness for this purchase. And 0.155 of a point is still not a wide result: push openness from 15 to 30 and the Q2 wins at 7.652, its largest margin anywhere in this study.

The 4.0 has a specific cause and it has not changed. QIDI's documented normal operating requirement is to run the Q2's enclosure open for polylactic acid (PLA) and PETG, or retained heat softens filament above the heat break and jams it. 3dwork.io jammed repeatedly through a first week, PCMag lost two days to one jam. Those are Rob's bulk materials, so the machine whose ABS credential is a sealed 65 °C chamber is one he would run open most of the time, which is when the fume containment stops working.

My reading: with ABS-GF occasional, there is no longer a capability the QIDI has and the Bambu lacks that Rob needs often enough to pay 3.5 points of reliability for. The remaining case for the Q2 is openness and $127.49, and both are real. A reader who would rather not print through Bambu Connect should buy the Q2 and accept the open lid.

Is the X2D worth $138.14 more than the P2S with its kit?

Still no, and the reason is cleaner than it was. The X2D AMS Combo is $955.19 all-in on 2026-09-06 against $817.05 for the recommendation. Its heated chamber is the best here, 9.5 on materials today against 7.2, top of the field, and CNC Kitchen confirmed a real 65 °C by thermocouple in about 20 minutes. At weight 15 rather than 20 that advantage is worth 0.345 of a point, and it loses more than that elsewhere: 0.375 to reliability at 6.0 against 7.5, 0.18 to value, less again on openness and practicalities, finishing at 6.980. Its magazine is also worse than the cheaper Bambu's, not better: one AMS has a single outlet, so it feeds one of the two nozzles only, which is 6.5 against 7.0. Raise materials to 35 and the X2D takes first at 7.325. That is the counterfactual for a buyer whose whole purchase is ABS-GF, and Rob has said his is not.

The best Bambu, and the best non-Bambu

The best Bambu is the recommendation: the P2S Combo plus Bambu's own $19.99 External Exhaust Fan Kit, $817.05 all-in on 2026-09-06, first at 7.240, nothing to buy later. That kit is the cheapest fume fix in this study and standard on the X2D. The ceiling is fixed: no chamber heater exists for the P2S at any price, so large ABS parts stay a warp risk, and a permanently loaded, dried ABS-GF lane still means adding a $139 AMS HT.

The best non-Bambu is the QIDI Q2 Combo at $689.56 all-in, third at 7.085 and $127.49 less. If the open enclosure worries a reader more than the price does, the Plus5 Combo at $955.19 is the same idea with a bigger chamber, materials at 8.3 and an unverified vendor claim to have fixed the jamming.

One result is worth stating plainly because it got weaker. Under the previous assumption a QIDI won all six weightings this study runs. Now those six split four ways: two to the P2S with its kit, two to the QIDI Plus5, one to the Q2 and one to the X2D. The field is close, and no configuration here dominates it.

The cheap option worth naming is the P1S AMS 2 Pro Combo at $615.19 all-in, sixth, which holds the study's highest reliability score, 8.0, on three years of record. It fails on materials rather than on quality: a passive chamber owners measure near 40 °C, so large ABS parts warp, and $49.48 of hardened parts before fiber. Materials today, 4.6.

Prices retrieved 2026-09-06; shipping free on all six. "Later" is the hardened nozzle and extruder the P1S needs before fiber.

The bare P2S Combo is left out of that table for width. It is identical to the first column except for the exhaust kit: materials 6.8, noise and fumes 8.0, total 7.15, $795.81 all-in.

Scores are out of 10 against weights summing to 100. All six have full evidence coverage.